Car park designers’ handbook
Jim Hill With contributions from
Glynn Rhodes, Steve Vollar and Chris Whapples
Published by Thomas Telford Publishing, Thomas Telford Ltd, 1 Heron Quay, London E14 4JD. URL: http://www.thomastelford.com Distributors for Thomas Telford books are USA: ASCE Press, 1801 Alexander Bell Drive, Reston, VA 20191-4400, USA Japan: Maruzen Co. Ltd, Book Department, 3–10 Nihonbashi 2-chome, Chuo-ku, Tokyo 103 Australia: DA Books and Journals, 648 Whitehorse Road, Mitcham 3132, Victoria First published 2005 Also available from Thomas Telford Books The Motorway Achievement volume 1. The British motorway system: visualisation, policy and administration. Edited by Sir Peter and Robert Baldwin. ISBN 07277 3196 3 The Motorway Achievement volume 2. Frontiers of knowledge and practice. Edited by Professor Ron Bridle and John Porter
A catalogue record for this book is available from the British Library ISBN: 0 7277 3438 5 # Thomas Telford Limited 2005 All rights, including translation, reserved. Except as permitted by the Copyright, Designs and Patents Act 1988, no part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior written permission of the Publishing Director, Thomas Telford Publishing, Thomas Telford Ltd, 1 Heron Quay, London E14 4JD. This book is published on the understanding that the authors are solely responsible for the statements made and opinions expressed in it and that its publication does not necessarily imply that such statements and/or opinions are or reflect the views or opinions of the publishers. While every effort has been made to ensure that the statements made and the opinions expressed in this publication provide a safe and accurate guide, no liability or responsibility can be accepted in this respect by the authors or publishers. Typeset by Academic þ Technical, Bristol Printed and bound in Great Britain by MPG Books, Bodmin, Cornwall
This book is dedicated to the memory of John Charles Cannon MA (Cantab), CEng, MICE, FIStructE
1931–2005 An outstanding engineer who, for 50 years, fought the effects of poliomyelitis with courage and determination.
Contents
Foreword Preface Glossary of terms Acknowledgements
1 Introduction 1.1 1.2 1.3 1.4
Historical note Advice and guidance Scope Design flexibility
2 Design brief 2.1 2.2
The client The brief
3 Design elements 3.1
3.2
3.3
3.4
3.5
3.6
The standard design vehicle (SDV): discussion 3.1.1 Length and width 3.1.2 Height 3.1.3 Wheelbase 3.1.4 Ground clearance 3.1.5 Turning dimensions 3.1.6 Recommended minimum diameters for turns up to 1808 between obstructions 3.1.7 Left side, right side or in the middle? Parking categories 3.2.1 Discussion 3.2.2 Car park categories Parking stalls 3.3.1 Discussion 3.3.2 Recommended dimensions for differing parking categories 3.3.3 Obstructions between stalls 3.3.4 Angled parking Aisle widths 3.4.1 Discussion 3.4.2 One-way-flow with reduced aisle widths 3.4.3 Two-way-flow-with reduced aisle widths 3.4.4 Manoeuvring on aisles 3.4.5 Turning between aisles Bin dimensions 3.5.1 Discussion 3.5.2 Recommended minimum bin dimensions for parking with 2.400 m-wide stalls Ramps and access-ways 3.6.1 Discussion 3.6.2 Recommended maximum vehicle gradients 3.6.3 Transitional slopes 3.6.4 Ramp projections into aisles 3.6.5 Storey height ramps
xi xiii xiv xvi
1 1 2 2 2
4 4 4
6 6 6 6 7 7 8 8 8 8 8 9 9 9 9 9 10 10 10 11 12 13 13 13 13 13 13 13 16 17 17 17
3.6.6 3.6.7 3.6.8 3.6.9 3.6.10 3.6.11 3.6.12 3.6.13
Side clearance Manoeuvring envelope Stall access One-way-flow ramp widths: discussion Ramp widths and angled parking Two-way-flow ramps Turning circle templates Two-way-flow: recommended minimum clear ramp widths 3.6.14 Scissors-type ramps 3.6.15 Side-by-side ramps 3.6.16 Circular ramps 3.6.17 Recommended minimum diameters for full circle ramps between limiting wall faces 3.6.18 Recommended minimum widths for circular ramp lanes between wall faces 3.7 Interlocking ramps 3.7.1 Stadium type 3.7.2 Circular type 3.8 Kerbs 3.9 Super-elevation 3.10 Parking deck gradients 3.11 Headroom and storey heights 3.12 Height limitations
4 Dynamic considerations 4.1
Discussion 4.1.1 Impact speeds 4.1.2 Effects of rain 4.1.3 Exit and entry rates and internal movement 4.1.4 Dynamic capacities for different stall widths and categories 4.1.5 Stopping distance 4.1.6 Speed limits 4.1.7 Dynamic capacities of ramps and access-ways 4.1.8 Dynamic capacities of cross-ramps and access-ways, per hour 4.1.9 Dynamic capacities of parking decks; calculations 4.1.10 Dynamic efficiency
5 Static considerations 5.1
Static 5.1.1 5.1.2 5.1.3
efficiency, discussion Relative efficiencies Area per car space Recommended capacities
6 Circulation design 6.1 6.2 6.3 6.4
6.5
Discussion How many levels? Roof considerations Circulation efficiency 6.4.1 Discussion 6.4.2 Shortest travel distance 6.4.3 Examples of circulation efficiency Parking times 6.5.1 Discussion
17 18 20 20 21 21 22 22 22 22 22 24 24 24 24 24 24 25 25 25 25
26 26 26 26 26 27 27 27 27 28 28 29
30 30 30 31 31
33 33 33 33 34 34 34 35 35 35
7 Circulation layouts 7.1 7.2 7.3
7.4 7.5
7.6
7.7
7.8
Discussion Dimensions used User-friendly features 7.3.1 Discussion 7.3.2 Simplicity 7.3.3 Crossovers 7.3.4 Circulation direction 7.3.5 Dead ends (culs-de-sac) Angled and right-angled parking: a comparison Split-level decks (SLDs) SLD 1 One-way traffic flow with an included rapid outflow route SLD 2 One-way traffic flow with an excluded rapid outflow route SLD 3 One-way-flow with side-by-side ramps (scissors type) SLD 4 Combined one-way-flows, three bins or more wide SLD 5 Combined one- and two-way-flows, three bins or more wide SLD 6 Two-way-flow with ‘combined’ ramps SLD 7 One-way-flow with an included contra-flow rapid exit route Sloping parking decks (SDs) SD 1 Single helix with two-way-flow SD 2 Single helix with one-way-flow and a rapid outflow route SD 3 Double helix, end connected with one-way-flow on the central access-way SD 4 Double helix, end connected with two-way-flow on the central access-way SD 5 Interlocking double helix, with one-way-flows SD 6 Combined helix, side connected with one- and two-way-flows SD 7 and 8 Double helix, side connected, with one-way-flows Combined flat and sloping deck (FSD) layouts FSD 1 Single helix with two-way-flow FSD 2 Single helix with one-way-flow and a rapid outflow route FSD 3 Combined helix, side connected with one- and two-way-flows FSD 4 Combined helix, side connected with one-way-flow FSD 5 Double helix, side connected with one-way-flow FSD 6 and 7 Double helix, side connected with one-way traffic flows FSD 8 Single helix with one-way-flow and an internal ramp Combined flat and sloping deck layouts with internal cross-ramps (VCM and WPD) VCM 1 One-way-flow with two one-way-flow ramps VCM 2 One-way-flow with end ramps VCM 3 Two-way-flow with a single end ramp VCM 4 One- and two-way traffic flows with a single ramp
37 37 37 37 37 37 38 38 38 38 43 44 46 48 50 52 54 56 59 60 62 64 66 68 70 72 75 76 78 80 82 84 86 88 91 92 94 96 98
7.9
7.10
7.11 7.12
7.13
WPD 1 Warped parking decks with one-way-flow Flat decks with storey height internal ramps (flat with internal ramps – FIR) FIR 1 One-way-flow decks with combined two-way-flow ramps at right-angles to the aisles FIR 2 One-way-flow decks with side-by-side (scissors type) ramps at right-angles to the aisles FIR 3 One-way-flow decks with combined two-way-flow ramps parallel with the aisles FIR 4 One-way-flow decks with separated one-way-flow ramps Minimum dimension (MD) layouts MD 1 One-way-flow between circular end ramps MD 2 Two-way-flow with a circular ramp at one end MD 3, 4 and 5 One- and two-way-flows, ten stalls wide MD 6, 7 and 8 One- and two-way-flows eight stalls wide (VCM type) MD 9, 10 and 11 One- and two-way-flows eight stalls wide (split-level type) Circular sloping decks (CSDs) CSD 1 Circular parking deck with two-way-flow Half external ramps (HERs) HER 1 Half spiral with one-way-flow HER 2 and 3 Straight ramps with one-way-flow HER 4 Straight ramps with one-way-flow, end located HER 5 Straight ramps with one-way-flow, end located External ramps (ERs) ER 1 Full circular with a two-way traffic flow ER 2 Full circular ramps each with a one-way traffic flow ER 3 Straight ramps with a one-way traffic flow ER 4 Storey height, straight ramps ER 5 Stadium-shaped interlocking ramps ER 6 Circular interlocking ramps
8 Stairs and lifts 8.1 8.2
8.3 8.4
Discussion Vertical and horizontal escape 8.2.1 Stairs, widths of flights 8.2.2 Vertical escape 8.2.3 Horizontal escape Escape distances Lift sizing
9 Disabled drivers and carers 9.1 9.2 9.3 9.4
Discussion Stall locations Stall dimensions Access
100 103
104 106 108 110 113 114 116 118 120 122 125 126 129 130 132 134 136 139 140 142 144 146 148 150
153 153 153 153 155 155 155 156
161 161 161 162 163
10 Cycles and motorcycles
165
10.1 Discussion 10.2 Cycle parking
165 165
10.3 Motorcycle parking 10.4 Lockers 10.5 Fiscal control
165 166 167
11 Security
169
11.1 11.2 11.3 11.4
169 169 170 170
Discussion Lighting, music and CCTV See and be seen Women-only car parks
12 Underground parking 12.1 Discussion
13 Lighting 13.1 Discussion 13.2 Emergency lighting
173 173
175 175 175
14 Signage
177
14.1 14.2 14.3 14.4 14.5
177 177 178 178 179
Discussion Directional signs Information signs Variable message sign systems Emergency signs
15 Drainage 15.1 Discussion
16 Fire escapes, safety and fire fighting
181 181
183
Discussion Escape distances Fire safety Fire-fighting measures Sprinklers Fire escapes
183 183 183 183 184 184
17 Fiscal and barrier control
187
17.1 Discussion 17.2 Control systems 17.3 Barrier control
187 187 188
16.1 16.2 16.3 16.4 16.5 16.6
18 Ventilation 18.1 18.2 18.3 18.4
Discussion Natural ventilation requirements Mechanically assisted natural ventilation requirements Mechanical ventilation requirements
19 Structure 19.1 19.2 19.3 19.4 19.5 19.6 19.7 19.8
Discussion Construction materials Joints Perimeter protection Concrete finishes Protective coatings Waterproofing Cambers
20 Appearance
191 191 191 191 191
195 195 195 196 196 197 197 197 198
201
20.1 Discussion 20.2 Appearance requirements
201 201
Appendix A
203
References
204
Index
205
About the authors
James Hill CEng FIStructE (ret’d)
Glynn Rhodes BSc (Hons) CEng MICE MIHT FConsE
In 1967 Jim founded the Hill Cannon Partnership (HCP) with John Cannon and has been involved in car park design since 1969. In 1970, they developed the Tricon structural system and in 1993 Jim patented the Vertical Circulation Module system (VCM). He is a past President of the British Parking Association and a regional Chairman of the Concrete Society. He is now a consultant to the practice, having retired in 1992, since when he has concentrated on the further development of VCM, designing appropriate circulation layouts for many projects and researching this book. He is currently writing a similar handbook on ‘good practice’ parking in the USA. Glynn is a senior partner of the HCP and has been involved in the design of 30 multi-storey car parks since 1986, two of which have been voted Best New Build car parks at the annual British Parking Awards. He also received the Ernest Davies Award for the best article published in Parking News entitled ‘Current Trends in the Design of Car Parks’. He has provided design advice for large underground car parking facilities in Manila, Kuala Lumpur (Petronas Towers), Zagreb and Dubai. Recent projects include the Jubilee car park in Harrogate (precast with 450 spaces), Merryhill Shopping Centre, West Midlands (precast with 1600 spaces) and Manchester Royal Infirmary (precast with 1600 spaces). Steve is a senior partner of the HCP and has been actively involved with car park design and parking related subjects since 1996: these include structured car parks, both above and below ground, as well as large capacity single deck layouts. His particular interest is in the provision of suitably located parking for disabled drivers, two wheeled traffic and general ‘wayfinding’ for both motorists and pedestrians alike. Recent design projects include Birmingham Airport (precast with 1700 spaces), Ocean Terminal; Edinburgh (precast with 1000 spaces) and Clarence Dock; Leeds (precast with 1600 spaces).
Stephen Vollar Eur Ing BSc CEng FIStructE MICE FConsE
Christopher Whapples BSc (Hons) CEng FIStructE FICE MIHT FConsE
A senior partner of the HCP, Chris has been involved in the design of parking structures for more than twenty years. He is a contributor to the IStructE publication Design recommendations for multi-storey and underground car parks and the Institution of Civil Engineers’ publication Recommendations for inspection, maintenance and management of car park structures. He has served on European technical committees and has presented papers on parking related subjects. His particular interest is in the development of new structural forms. Recent design projects include St. Andrews; Norwich (steel frame with 1100 spaces), Sundials; Amersham (steel frame with 550 spaces) and Designer Outlet Village, Livingston (in situ with 1600 spaces).
Foreword
Jim Hill has spent the last 35 years in the development of car park design and this experience has given him a unique insight into the reasons why some buildings operate successfully and others, of a similar size and activity, do not. The choice of the correct circulation layout is a subject that he considers to be of prime importance in the creation of an efficient parking building. Both as a consumer of parking services and a former parking manager, it always intrigues me why some parking layouts are easily navigated and yet others test one’s patience? As an engineer, I think logically and admire the ‘art of parking’ created by my fellow colleagues; as a consumer I want to be able to park my car as quickly and as effectively as I can and get on with the business in hand, be it work or play; this is especially true if I have children with me. My experience has taught me that parking is a means to an end; it is the first and last impression of my ‘destination’; it needs to be good if I’m to contemplate returning there again and again. This is especially true in the retail and commercial world where (hopefully) my custom is valued. It is equally true when I visit an unfamiliar town or city, park at a rail station, or simply spend a day at leisure someplace. Equally important is the need to feel intuitively safe and welcome wherever I choose to park. Complex layouts, frustration with queues and conflict with others who are manoeuvring about in or out of parking spaces, or sometimes in what seems like a never-ending set of twists and turns to get in or out of the car park in the first place, only serve to increase my sense of ‘uncared for’ by the owner or operator. This book, describes and illustrates some 60þ variations on the many ‘layout themes’, no doubt there are others. Their advantages and disadvantages are discussed, recommendations made for their practical application and suggestions made for other layouts that should also be considered. More than just discussing layouts, the author has shown how ramps can be prevented from projecting excessively into traffic aisles, how to assess dynamic capacity and efficiency, and the many other considerations that go to make up the design process. The matters dealt with in Chapters 8 to 20 such as the current requirements for people with mobility impairments, pedestrian access, security, ventilation, etc. have been written with the help of his partners, all parking experts in their own right. In the author’s opinion, effective design is based upon common sense, a little crystal ball gazing and experience: it is not a precise art. He suggests that, provided drivers will want to frequent the car park and clients are willing to pay for it, little else matters. I wouldn’t want to disagree with him, but my comments about being ‘welcome’ at any parking facility are the key to its success. If the operator wants to do business, good customer service is vital; to do that needs good design. This book addresses the subject of car park design, especially the design of circulation layouts, in a practical manner and can be easily
understood by anyone with an interest in the subject. It will help to identify examples of best practice in making our parking facilities more accessible to all. The book is also a useful reference for those considering the Park Mark1 Safer Parking Scheme. Kelvin Reynolds Kelvin is Director of Technical Services at the British Parking Association and Head of the Safer Parking Scheme.
Preface
Information on the design of vehicle circulation systems in car parks is hard to find: had it not been so this book, probably, would not have been written. To my knowledge, special features and relative efficiencies of car parks have never before been discussed in any great detail. Many designers are unaware of the advantages of using a particular layout system over another and it is a major purpose of this book to redress that imbalance. In 1968, John Cannon and I first became involved in car park structures when we were retained to design the foundations and nonstandard elements for a proprietary precast concrete system. A local car park incorporating this system had become the subject of adverse comment by many who used it, convincing us that we could do better ourselves. Our first effort was to develop a clear-span structure that was efficient, economical, aesthetically pleasing and capable of being constructed using structural steel as well as precast and cast in situ concrete: this was a successful venture and after more than 35 years it is still being used in many car park designs. In time, however, it became clear that no matter how efficient the structural solution was and how attractive the architectural appearance, if it was wrapped around a poor choice of circulation layout the result was yet another unpopular car park. In many under-used car parks, the reason for their unpopularity is not that that they have been allowed to become dirty and/or dingy (conditions that by themselves would not normally put off most motorists), but rather that they suffered from a poor choice of internal layout. Of the many buildings inspected, the most unpopular have, invariably, incorporated inappropriate circulation designs. Rather than giving these car parks an expensive cosmetic ‘makeover’, the money would have been better spent on improving the layout, even at the cost of losing, possibly, a few parking stalls. Over the years, as we became more experienced, so our awareness of the number of different layouts available increased. Fifteen years ago I decided to list them and recommend when and where they could be put to best use. This endeavour was interrupted in 1992 by the development and promotion of the vertical circulation module (VCM) circulation system. It was just as well, as the number of different layouts has risen even further since then. Some have been rejected as being impractical or just plain whimsical, but those that are featured in this book are practical and have been constructed somewhere but not always in the UK. With more than 6000 car parks in the UK, 30 000 in the USA and many thousands more in the rest of the world, it is unlikely that all of the possible variations will have been covered, and if any reader is aware of a practical circulation layout substantially different from those featured and lets me know, if it is included in a future edition they will be acknowledged as the source. Finally, I would like to thank my wife Rosalie who not only accompanied me on my travels around the car parks of several countries without complaint, but was also of invaluable assistance in suggesting improvements to the text and correcting my grammatical errors: any that remain are entirely my own fault.
Glossary of terms
Access-way or crossway A traffic lane without adjoining stalls laid flat or to a slope not exceeding 5%, also capable of being used by pedestrians. Aisle A traffic lane with adjoining stalls on one or more sides. Bin Used to denote the dimension across an aisle and its adjacent stalls. (A half bin has stalls only on one side.) Circulation efficiency A method of comparing the travel distance required to search the stalls, in any particular car park, with the minimum travel distance. (Given as a percentage.) Congestion Applies to traffic that is unable to flow freely. Cross-ramp An inclined traffic lane connecting the aisles in adjacent bins, laid to a slope greater than 5%. Deck A single floor that extends over the plan area of a parking building. Des Recs A shortened form of words describing the Design Recommendations for Multi-storey and Underground Car Parks, 3rd edition, published in June 2002 by the Institution of Structural Engineers. Dynamic capacity A measure of the rate that traffic can pass a given location within a car park. (Given in vehicles per hour.) Dynamic efficiency A measure of the ability of a car park to process vehicles under normal operating conditions. Excluded Applies to an inflow route that is separated from an outflow route. Extended Applies to any traffic route that is not rapid. Included A flow route that is located within the circulation pattern of another. Inflow Applies to the search path for traffic within a car park.
Manoeuvring envelope (ME) The boundaries established by the minimum turning circle when entering a crossway or ramp, outside of which a vehicle is unable to manoeuvre without reversing. MPV The initials for a multi-purpose vehicle. MSCP The initials for a multi-storey car park. One-way-flow Traffic flowing in a single direction on an aisle. Outflow Applies to traffic exiting from a car park. Ramp Any traffic lane, without adjoining stalls, that provides access to or from parking at different levels. Rapid Applies to a short route for inflow or outflow traffic. Stall The parking area allotted to a single vehicle, exclusive of any other adjoining area. Stall pitch The spacing for stalls, normal to an aisle, for a particular angle of parking. Static capacity The total number of stalls contained within a designated area or complete car park. Static efficiency The area of the parking decks divided by the static capacity and given as an area per stall. SUV The initials for a sports utility vehicle. Swept path The width on plan established by a vehicle for any given radius of turn. Two-way-flow Traffic flowing in both directions on an aisle, ramp or crossway. Vph Vehicles per hour.
Acknowledgements
Figs 1.1, 3.1, 3.2, 3.3, 3.5(a) and (b), 3.7, 3.8, 3.9, 3.10, 3.11, 3.17, 3.19, 3.20, 6.1, 7.2, 7.3, 7.5, 7.7, 7.8, 7.9, 8.1, 9.1, 10.1(a), 11.1, 12.1, 13.1, 14.1, 15.1, 16.1, 17.1, 19.1 and 20.1 Hill-Cannon archives. Figs 7.4 and 7.6 courtesy of Dundec Ltd. Fig. 7.10 courtesy of Norwest Holst. Fig. 10.2(c) courtesy of Falco. Fig. 10.3(d) courtesy of Motoloc Ltd. Fig. 18.17 courtesy of PSB (UK) Ltd.
7
Circulation layouts
7.1 Discussion
Of the more than 5000 structured car parks believed constructed in the UK alone, it can be readily appreciated that no single person can have knowledge of every circulation layout variation that has been proposed and built. Practical considerations, personal experience and the constant pressures for financial economy render it reasonable to assume that the examples shown, all of which have been featured or built during the past 35 years, provide the basis for most of the self-parking buildings that exist at the present time. The design of a satisfactory circulation layout is one of the most important factors governing user appreciation and yet many designers are unaware of the large variety of options from which they may choose and their suitability for the intended purpose. The following examples are all practical layouts and form the basis upon which most self-parking facilities have been designed. Some are more popular than others and some are significantly defective in circulation design, static and dynamic efficiency. If designers are to gain confidence in developing solutions to solve particular problems, then it is desirable that they should know the strengths and weaknesses of individual layouts in order to make an informed choice.
7.2 Dimensions used
There are few precise dimensions that must be adopted for the design of parking structures. Dimensions for the individual elements can vary and are also affected by the parking angle (that varies the bin width) in one direction and the stall pitch (that varies the overall length) in the other direction. The main concern is that motorists and clients are content. It is overly laborious and unnecessary to keep mentioning all of the variations that can occur in practice and so dimensions for the featured layouts will be based upon those recommended for 908 parking with stall dimensions of 2.400 m 4.800 m, aisle widths of 6.000 m (oneway flow), 7.000 m (two-way flow) and a storey height of 3.000 m. In the layouts shown in the following pages, the overall aisle lengths are sometimes shown less than those given for the width; nevertheless, the length of the aisle will determine the ‘length’ of a layout and the dimension over the bins will determine its ‘width’.
7.3 User-friendly 7.3.1 Discussion features There are many existing car parks where, in retrospect, it can be seen that the layout would have been much better if only the designer had recognised that a problem existed. In such cases, if improvements had been incorporated at the design stage, they need not have cost more to implement or reduced static capacity. They could even have enhanced the market value by being more ‘user friendly’ to the parking public. It is, also, a relatively simple matter to spoil a potentially acceptable circulation layout by over complication, or by the introduction of unnecessary and unfriendly features. 7.3.2 Simplicity The basic tenet of all circulation design is to ‘keep it simple’. What, at first, might look like a clever idea to a designer could well end up as a
37
motorist’s nightmare. In a structured car park the layout should endeavour to replicate the openness of a surface car park. To this end, it is desirable to eliminate, as far as possible, vertical structure that interferes, both visually and physically, with the free movement of vehicles and pedestrians. Turning directly from one lock to the other is not a popular manoeuvre. If possible all turns should be in the same direction and not more than 908 at a time. When located under other types of building, it is not always possible to create the most desirable layout. Attempts should be made to minimise the visual impact of large vertical elements and locate them away from the circulation routes, if at all possible. 7.3.3 Crossovers Crossover conditions should be avoided. When on a traffic aisle and searching for the first available space, it is disconcerting and potentially dangerous to find a car suddenly appearing at right angles from behind a parked vehicle. The driver of this car may also be concentrating on finding a space in which to park, or intent only on leaving the facility as quickly as possible. A user-friendly circulation layout should not hold surprises for drivers who should be able to observe the movements of other vehicles well before there is a need to take avoiding action. 7.3.4 Circulation direction The direction of circulation has little effect upon circulation efficiency in one-way-flow systems. Provided that the route is of an adequate width it matters little in which direction the traffic is made to flow. It has been said that left-turning circuits are not as popular in one-way-flow systems as turning to the right. However, when vehicles are travelling down the middle of an aisle drivers are biased to the right thereby providing a much better view of openings on the left. When a two-way-flow ramp occurs in a one-way-flow layout it is preferable to have a left-turning circuit whereby traffic drives on the correct side of the ramp. When entering a traffic aisle from a right-turning ramp, a front-seat passenger could obscure traffic approaching from the left, but when traffic approaches from the right the driver’s lateral vision is relatively unimpaired. Turning right onto an exit barrier enables a ticket to be inserted more easily into the acceptor machine than when turning to the left. When the entry/exit lanes are located side-by-side, right turning circuits are preferable if a crossover situation is to be avoided. None of these points are important enough to dictate the direction of flow by themselves, but it is useful to appreciate that they occur when considering the flow direction. 7.3.5 Dead ends (culs-de-sac) When viewing down a ‘dead-end’ aisle, it is difficult to see the parking situation more than three or four stalls away. For good practice, and if unnecessary manoeuvring is to be avoided, it should be the limiting factor.
7.4 Angled and right-angled parking: a comparison
38
Members of the public and some clients, ask why angled parking is not used more frequently in the UK. They point out that it is popular in the USA and, for those who have used it, it is a popular parking format but, in the UK, layouts with 908 parking occur more often in towncentre car parks than any of the other types. Figure 7.1 shows a basic UK town-centre-type split-level layout with 908 parking. It is 28 stall widths in length with 96 stalls on each deck.
Car park designers’ handbook
Fig. 7.1 Angled and right-angled parking: a comparison
The area of the deck is 2096.6 m2 producing an average of 21.840 m2 per stall. Figure 7.1 also shows the same basic layout with 708 parking. It is 28 stall widths in length with 92 stalls on each deck. The area of the deck is 2196.8 m2 producing an average of 23.620 m2 per stall. The difference of 1.780 m2 per stall represents an increase of 8% in area and a consequent increase in construction costs. The 708 layout, at 71.512 m, is 4.312 m longer than the 908 layout, representing an increase of 6.5% in length while containing 4% fewer vehicles. The width at 30.724 m is 484 mm narrower than the 908 layout representing a reduction of 1.5%. The traffic aisles for the 708 layout at 4.700 m wide are 1.300 m less than those for the 908 layout, reducing the separation distance between vehicles and pedestrians on the aisles. If the stall widths in a 908 car park were increased by 8%, to 2.550 m, both layouts would be rendered similar in area and cost. In this eventuality, it is reasonable to ask whether 908 parking with 2.550 mwide stalls and 6.000 m-wide aisles would be more popular than 708 parking with 2.400 m-wide stalls and 4.700 m wide aisles? It is a question that can only be answered by designers and clients, individually. Widening the traffic aisles in the 708 car park will increase construction costs by about 0.6% for every 100 mm increase in width. As the parking angle reduces, so the building length increases and the aisle widths narrow even further. At a parking angle of 458, a 96-space
Circulation layouts
39
per deck building will need to be 95.000 m in length, (41% longer) and even with aisle widths reduced to 3.600 m, the car space requirement will be some 25% greater than for the 908 car park (see Section 5.1.1). A two-bin, split-level car park with 908 parking could increase its stall widths to 3.000 m, and retain its 6.000 m-wide aisles without exceeding the area per car space for a two-bin 458 car park with 2.400 m-wide stalls and 3.600 m wide aisles. In the USA, many structured town-centre-type car parks incorporate 908 parking. Stalls with 608 angles, widened aisles and a two-way traffic flow are sometimes used for retail shopping at surface level and 708 to 808 angles for large Cats 3 and 4 buildings of the SD and FSD series, SD 2, 3 and 4 being particularly popular in the southern and western USA.
40
Car park designers’ handbook
Index
Page numbers in italics refer to illustrations and diagrams. access ways 13, 14, 15 see also ramps dynamic capacity 27–28 aesthetics of design 200, 201–2, 202 circular sloping deck types 124, 125 air change rates, ventilation 192 aisles angled stalls 11 dead ends 38 inflow capacity 36 minimum widths one-way-flows 13 two-way-flows 13 pedestrians in 11 with angled parking stalls 11 ramp entries 21 ramp projections into 17 reduced one-way-flows 11, 19 two-way-flows 12 turning between 12, 13 vehicles crossing 26–7 viewing angles 8 widths 10–11 angled stalls 10 angles 11, 12 circulation efficiency 38–40, 39 design implications 39–40, 39 dynamic efficiency 29 minimum dimensions 13 pedestrians in aisles 11 ramp widths 21 barriers 186 exit 38 numbers of 189 two-way-flow 188 Birmingham airport, car park 152 camper vans 6 capacities medium stay car parks 31 short stay car parks 31 tidal car parks 32 car parks see also multi-storey car parks as motorists’ destination influences 1–2 user friendly 2, 37–9 CCTV 168, 169–70 optimum monitoring 169–70 presence of 169 changes of use, car parks 2–3 circular decks, two-way-flow 126, 127 circular ramps 22, 24 end one-way-flow 114, 115 two-way-flow 116, 117
full, two-way-flow 140, 141 turning circles 139 two full, one-way-flow 142, 143 circular sloping decks 124, 125 see also CSD series user-unfriendliness 125 circulation design, simplicity 37–8 circulation efficiency angled stalls 38–40, 39 crossovers 38 importance of 35–6 indicating 34 combined flat and sloping decks internal cross-ramps see also VCM and WPD series pedestrian access 91 combined helix one- and two-way-flows side connected 70, 71, 80, 81 one-way-flow, side connected 82, 83 contra-flow rapid exit, one-way-flow types 56, 57 control signs 178 control systems barriers 186 exit 38 numbers of 189 two-way-flow 188 disabled drivers 163 pay and display 187 payment by mobile phone 187–8 payment on exit 186, 187 payment on foot 187 tag systems 188 crossovers 13, 14, 15 avoiding 38 manoeuvring envelopes 18, 19, 20 CSD 1 (circular deck/two-way-flow) 126, 127 static efficiency 127 cycle parking lockers 164, 165 stands for 165, 166 decks combined flat and sloping 91 directional markings 177 drainage falls 181 dynamic capacity 28–9 exposed effects of rain 26 roofing 33–34, 195–6 stopping distances on 27 temperature differences 196 waterproofing 33 flat, with internal ramps 103 frost prevention 198 gradients 25 level indicators 176, 178
205
decks (continued ) metal plate 196 surface abrasion 198 washing-down facilities 181 waterproofing 197–8 deflections, structural 198–9 design aesthetics 200, 201–2, 202 angled stalls, implications 39–40, 39 briefs 4–5 existing 37 questionnaires 4 design and build projects 201 Design recommendations for multi-storey and underground car parks (Des. Rec.) 1 ramps 16, 16 dimensions disabled parking stalls 162, 162 stalls area per car space 31 length 9 width 9, 27 disabled drivers see also disabled pedestrians flat and sloping decks 75 hillside car parks 161 separation of 163 sloping parking decks 59 tariffs for 163 disabled parking stalls 160 dimensions 162, 162 legal requirements 161 location parameters 161–2 random 162 numbers 161 supervision 162 disabled pedestrians see also disabled drivers fire escapes 156, 183 lift buttons 177 ramps 15, 156 refuges for 154 viewing panels 177 double helix interlocking, one-way-flow 68, 69 one-way-flow end connected 64, 65 side connected 72, 73, 86, 87 two-way-flow, end connected 66, 67 drainage deck falls 181 gully outlets 198–9 location 181 petrol interceptors 181 protection of 180 roofs 181 stair cores 181 ventilating 181 washing-down 181 driver frustration complex designs 37–8 potential conflict 49, 51, 129 stall searching 35, 73 dry-risers 154, 184 dynamic capacity decks 28–9
206
entries 26 exits 26 ramps 27–8 dynamic efficiency, angled stalls 29 efficiency see circulation efficiency; dynamic efficiency; static efficiency emergency signs 179 lighting 175, 179, 183 entries dynamic capacity 26 two-wheeled vehicles 165 environment, aesthetics 200, 201–2, 202 ER 1 (full circular ramps/two-way-flow) 140, 141 alternatives to 141 ER 2 (full circular ramps/one-way-flow) 142, 143 as alternative 141 alternatives to 143 ER 3 (straight ramps/one-way-flow) 144, 145 alternatives to 145 ER 4 (storey height straight ramps) 146, 147 ER 5 (stadium-shaped interlocking ramps) 148, 149 ER 6 (circular interlocking ramps) 150, 151 exit barriers, ticket insertion 38 exit routes dynamic capacity 26 rapid 36 exits emergency 183 ramps, headroom 15 two-wheeled vehicles 165 external ramps 138, 139 see also ER series FIR 1 (one-way-flow/two-way ramps/right angles) 102, 104, 105 alternatives to 105 circulation efficiency 35 static efficiency 105 FIR 2 (one-way-flow/scissors ramps) 106, 107 alternatives to 107 static efficiency 107 FIR 3 (one-way-flow/two-way ramps/parallel) 108, 109 alternatives to 109 static efficiency 109 FIR 4 (one-way-flow/one-way ramps) 110, 111 alternatives to 111 static efficiency 111 fire alarms 183 fire escapes access to 153–4 disabled pedestrians 156, 183 distances from 155–6, 183 horizontal 155 routes to 183 stairs as 153, 154–5 fire fighting 182, 183–4 lifts 184 smoke containment 184 sprinklers 184 fire lobbies 154–5, 154 fire regulations, stairs as fire escapes 153 fire safety strategies 183 flat decks external ramps, capacity 31 internal ramps 103
Car park designers’ handbook
flat decks with internal ramps see also FIR series multi-bin systems 103 ramp gradients 103 flat and sloping deck layouts 75 see also FSD series disabled drivers 75 pedestrian movements 75 four-wheel drive (4WD) vehicles 6 Freyssinet, Eugene 1 frost prevention, decks 198 FSD 1 (single helix/two-way-flow) 76, 77 as alternative 79 alternatives to 77 static efficiency 77 FSD 2 (single helix/one-way-flow/rapid outflow) 78, 79 as alternative 53 alternatives to 79 static efficiency 79 FSD 3 (combined helix/side connected/one- and two-way-flows) 80, 81 as alternative 51, 53 alternatives to 81 static efficiency 81 FSD 4 (combined helix/side connected/one-way-flow) 82, 83 as alternative 51 alternatives to 83 static efficiency 83 FSD 5 (double helix/side connected/one-way-flow) 74, 84, 85 alternatives to 85 static efficiency 85 FSD 6 (double helix/side connected/one-way-flow) 86, 87 FSD 7 (double helix/side connected/one-way-flow) 86, 87 FSD 8 (single helix/one-way-flow/internal ramp) 88, 89 alternatives to 89 static efficiency 89 gradients parking decks 25, 59 disabled drivers 59 sloping 59 ramps pedestrian 24 vehicle 15, 16–17, 16, 18, 103 single storey rise 103 ground clearances, standard design vehicles 7–8, 10 half external ramp types 128, 129 see also HER series capacity 31 driver conflict in 129 half external ramps, vehicle 126, 127 half spirals, one-way-flow types 130, 131 headroom 25 light fittings 25 height limitation gantries 25, 25 standard design vehicles 6, 10 helix see combined helix; double helix; single helix HER 1 (half spiral/one-way-flow) 130, 131 HER 2 & 3 (straight ramps/one-way-flow) 130, 131 alternatives to 133
Index
HER 4 (straight ramps end located/one-way-flow) 134, 135 alternatives to 135 HER 5 (straight ramps end located/one-way-flow) 136, 137 alternatives to 137 hillside conditions disabled drivers 161 multi-storey car parks 15 impacts protection from 196–7 speeds 26, 196 inhabited layouts, definition 33 interlocking double helix, one-way-flow type 68, 69 interlocking ramps circular type 24, 150, 151 stadium type 24, 148, 149 internal environmental monitoring 192 kerbs, pedestrian separation by 24–5 lengths parking stalls 9 standard design vehicles 6, 10 levels, optimum numbers 33 lifts buttons, disabled pedestrians 177 capacity per hour 158 considerations for 153 door widths 157, 161 fire fighting 184 long stay car parks 153, 157 medium stay car parks 153, 157 short stay car parks 153, 157 space requirements 157 supermarket requirements 156–7 tidal car parks 157 lighting 174 controls 175 emergency 175, 179, 183 signs 175, 185 fittings, headroom 25 and painting 175 security 169, 175 top decks 175 limosines in multi-storey car parks 7 stretched 7 lockers cycles 164, 165 helmets/clothes 166 long stay car parks 9 capacities 31 flat and sloping decks 75 lifts 153, 157 recommendations for 55, 57, 63, 97 main terminal car parks see long stay car parks manoeuvring envelopes (ME) historical 1–2, 2 ramps 18, 19, 20 stall access 18, 19, 20 market values, multi-storey car parks 3 MD 1 (one-way-flow/circular end ramps) 112, 114, 115 as alternative 121 alternatives to 115
207
MD 1 (one-way-flow/circular end ramps) (continued ) static efficiency 115 variations 115 MD 2 (two-way-flow/one circular end ramps) 116, 117 alternatives to 117 static efficiency 117 variations 117 MD 3 (one-way-flow/10 stalls wide) 118, 119 static efficiency 119 MD 4 (two-way-flow/10 stalls wide) 118, 119 static efficiency 119 MD 5 (two-way-flow/sloping decks/10 stalls wide) 118, 119 static efficiency 119 MD 6–8 (one- and two-way-flows 8 stalls wide) 120, 121 as alternative 123 alternatives to 121 static efficiency 121 MD 9–11 (one- and two-way-flows/8 stalls wide/split levels) 122, 123 alternatives to 123 static efficiency 123 medium stay car parks 9 capacities 31 large-capacity 45 lifts 153, 157 recommendations for combined flat and sloping decks 93, 97 sloping decks 61, 73 split level decks 47, 57 message signs, variable 34, 67, 81, 89, 115, 178–9 metal plate decks 196 minimum dimension layouts 113 see also MD series underground 112, 113 motorcycle parking free-standing 164, 165–6, 166 hard surface 166 helmet/clothes lockers 166 security surveillance 166 motorists’ destinations, car park influences 1–2 multi-purpose vehicles (MPV) 6 multi-storey car parks (MSCP) aisle viewing angles 8 categories 9 changes of use 2–3 first 1 hillside conditions 15 market values 3 running costs 187 sale of 2–3 music, and security 169 natural ventilation 191 obstructions, between parking stalls 9–10 occupancy maximum 154 notional 153–4 one- and two-way-flow types combined, threeþ bins wide 52, 53 combined helix side connected 70, 71, 80, 81 eight stalls wide 120, 121 split-level 122, 123 single ramp 98, 99 ten stalls wide 118, 119
208
one-way-flow aisle widths minimum 13 reduced 11, 19 circular ramps 22, 24 preference for 8 ramp widths 20–1 one-way-flow types see also one- and two-way-flow types combined, threeþ bins wide 50, 51 combined helix, side connected 82, 83 contra-flow rapid exit 56, 57 double helix end connected 64, 65 side connected 72, 73, 86, 87 end ramps 95, 96 circular 114, 115 excluded outflow 28–9, 29, 42, 46, 47 full circular ramps 142, 143 half spiral 130, 131 interlocking double helix 68, 69 internal ramps 92, 93 one-way ramps, separated 110, 111 rapid outflow 44, 45 capacity 31 circulation efficiency 35 scissors ramps 48, 49 at right angles 106, 107 single helix internal ramps 88, 89 rapid outflow 63, 64, 78, 79 straight ramps 132, 133, 144, 145 end located 134, 135, 136, 137 two-way ramps at right angles 104, 105 parallel 108, 109 warped decks 100, 101 outflow excluded rapid 46, 47 rapid 44, 45, 62, 63 overhead signage 176, 177 painting, light colours 175 parking stalls see stalls partially sighted, guidelines 177 pay and display 187 pay stations, signs 178 payment by mobile phone 187–8 on exit 186, 187 on foot 187 pedestrians see also disabled pedestrians access flat and sloping decks 91 angled stalls 11 encumbered 26 fire escapes access to 153–4, 183 distances from 155–6, 183 stairs as 153, 154–5 flat and sloping decks 75 guard rails 197 lifts 153 ramps 16 gradients 24 layouts 156, 156 split-level decks 43
Car park designers’ handbook
signage 177–8 sloping decks 59 and vehicle ramps 15 kerb separation 24–5 petrol interceptors, drainage 181 plans, availability 178 powered two wheelers (PTW) facilities for 164, 165 separate entries and exits 165 rain effects on decks 26 effects on stopping distances 27 ramps (pedestrian) 16 gradients 24 regulations 43 split-level decks 43 ramps (vehicle) see also access ways aisles, projections into 17 circular 22, 24 one-way-flow 142, 143 two-way-flow 140, 141 cross- 13, 14, 15 dynamic capacities 27–8 end 95, 97 circular 114, 115, 116, 117 exits, headroom 15 gradients 15 recommended 16–17, 16, 18 ground clearance on 7–8 half external 126, 127 interlocking circular type 24, 150, 151 stadium type 24, 148, 149 internal 88, 89 internal cross- 91 manoeuvring envelopes 18, 19, 20 open-aspect 14 outer clearances 14, 15 pedestrians and vehicle 15 scissor-type 22, 23 scissors, one-way-flow types 48, 49, 106, 107 separated, one-way-flow types 110, 111 side-by-side 22 storey height 17, 18, 103, 105 straight one-way-flow 132, 133, 134, 135, 136, 137, 144, 145 storey height 146, 147 two-way, one-way-flow types 104, 105, 108, 109 widths and aisle entry efficiency 21 angled stalls 21 one-way-flow 19, 20–1 turning circles 22, 23 two-way-flow 22 rapid exit routes 36, 78, 79 refuges, disabled pedestrians 154 reinforced concrete structures 195 finishes 197 life expectation 195 shrinkage joints 196 retail outlets short stay car parks 26 supermarkets, lift requirements 156–7
Index
roofs exposed decks 33–4, 195–6 drainage 181 running costs, multi-storey car parks 187 Safer Car Parks scheme 169 sales, multi-storey car parks 2–3 scissor-type ramps 22, 23 one-way-flow (SLD 3) 48, 49 scissors ramps one-way-flow types 48, 49 at right angles 106, 107 SD 1 (single helix/two-way-flow) 60, 61 as alternative 55, 63, 77, 97 alternatives to 61 congestion 61 static efficiency 61 SD 2 (single helix/one-way-flow/rapid outflow) 62, 63 alternatives to 63 static efficiency 63 SD 3 (double helix/end connected/one-way-flow) 64, 65 as alternative 67, 69, 89, 101 alternatives to 65 static efficiency 65 SD 4 (double helix/end connected/two-way-flow) 66, 67 as alternative 67, 69, 89 alternatives to 67 static efficiency 67 SD 5 (interlocking double helix/one-way-flow) 58, 68, 69 as alternative 51, 53, 67, 89 static efficiency 69 SD 6 (combined helix/side connected/one- and two-way-flows) 70, 71 alternatives to 71 static efficiency 71 SD 7 (double helix/side connected/one-way-flows) 72, 73 alternatives to 73 static efficiency 73 SD 8 (double helix/side connected/one-way-flows) 72, 73 alternatives to 73 static efficiency 73 searching stalls inefficient 51, 53, 81, 83 traffic congestion 73, 81 security CCTV 168, 169–70 car park shapes 170 optimum monitoring 169–70 presence of 169 lighting 169 motorcycle parking 166 music as aid 169 public perceptions 169, 170, 175 women-only car parks 170 short stay car parks 9 capacities 31 large-capacity 45 lift requirements 156–7 lifts 153, 157 recommendations for combined flat and sloping decks 93, 97 sloping decks 61, 73 split-level decks 47, 57 retail outlets 26 side-by-side ramps 22
209
signage control 178 deck levels, indications 176, 178 deck markings, directional 177 emergency 179 lighting 175 headroom 25 overhead 176, 177 pay stations 178 pedestrians 177–8 schedule 179 variable message 34, 67, 81, 89, 115, 178–9 single helix one-way-flow internal ramps 88, 89 rapid outflow 62, 63, 78, 79 two-way-flow flat and sloping decks 76, 77 sloping decks 60, 61 SLD 1 (one-way-flow/rapid outflow) 44, 45 as alternative 47, 57 alternatives to 45 capacity 31, 45 circulation efficiency 35, 45 static efficiency 45 SLD 2 (one-way-flow/excluded outflow) as alternative to FSD series 89 to SD series 65, 67, 71, 73 to SLD series 45 to VCM series 95 alternatives to 47 static efficiency 47 SLD 3 (one-way-flow/scissors ramps) 48, 49 as alternative 81, 85, 93 alternatives to 49 capacity 31 static efficiency 49 SLD 4 (combined one-way-flows, threeþ stalls wide) 50, 51 alternatives to 51 circulation efficiency 51 SLD 5 (combined one- and two-way-flows, 3þ bins wide) 52, 53 as alternative 83 alternatives to 53 static efficiency 53 SLD 6 (two-way-flow/combined ramps) 54, 55 as alternative 49, 61, 77 alternatives to 55 static efficiency 55 SLD 7 (one-way-flow/contra-flow exit) 56, 57 as alternative 97, 99 alternatives to 57 static efficiency 57 sloping parking decks (SD) see also SD series definition 59 disabled drivers 59 parking gradients 59 pedestrian considerations 59 smoke control 184, 192 detectors 192 speed limits, imposition of 27 split-level decks (SLD) see also SLD type series
210
advantages 43 pedestrian ramps in 43 popularity 43 sports utility vehicles (SUV) 6 sprinklers 184 staff parking see tidal car parks stairs cores, drainage 181 as fire escapes fire lobbies 154–5, 154 fire regulations 153 widths 155 stalls see also angled stalls; disabled parking stalls; parking decks access, manoeuvring envelopes 18, 19, 20 dimensions area per car space 31 length 9 width 9, 27 driver searches 35 dynamic capacity 27 obstructions between 9–10 rectangle 6, 9 searching inefficient 51, 53, 81, 83 traffic congestion 73, 81 static efficiency 30–1 standard design vehicles (SDV) see also vehicles 95factor 6, 10 departures from 6, 7 ground clearance 7–8, 10 height 6, 10 length 6, 10 turning diameters 8, 10 wheelbase 7, 10 width 6, 10 static efficiency definition 30 external bins 30 internal bins 31 single bins 30 two-bin layout 30 steelwork 195 coatings 197 storey height ramps 17, 18, 103, 105 structure alternative materials 195 deflections 198–9 reinforced concrete 195 finishes 197 life expectation 195 shrinkage joints 196 steelwork 195 coatings 197 supermarkets, lift requirements 156–7 surveillance see CCTV; lighting; security swept paths, turning circles 22, 23 tag systems of payment 188 tariffs see control systems temperature differences, exposed decks 196 tidal car parks 9, 49 capacities 32 with flow reversal 69 lifts 157
Car park designers’ handbook
recommendations for flat and sloping decks 97 sloping decks 61, 63, 65, 69 split level decks 49, 55, 57 two-way-flow, ramps 21–2 top decks see decks, exposed turning circles circular ramp systems 139 minimum dimension layouts 113 standard design vehicles 8, 10 swept paths 22, 23 two-bin layout, static efficiency 30 two-way-flow aisle widths minimum 13 reduced 12 circular decks 126, 127 circular ramps 24 end 116, 117 full 140, 141, 142, 143 traffic congestion 61 vehicles crossing 26–7 two-way-flow types see also one-and two-way-flow types with combined ramps 54, 55 double helix, end connected 66, 67 single end ramp 96, 97 single helix, sloping decks 60, 61 underground parking 172 constraints 173 efficiency 173 minimum dimension layouts 112, 113 ventilation 190, 191–2 uninhabited layouts, definition 33 USA, high level parking 33, 34 user-friendly car parks 2, 37–9 user-unfriendly car parks 125 variable message signs 34, 67, 81, 89, 115, 178–9 VCM 1 (one-way-flow/internal ramps) 90, 92, 93 as alternative to FIR series 105, 107, 109, 111 to FSD series 81, 83, 85, 89 to SD series 65, 67, 71, 73 to SLD series 45, 47, 51, 53, 57 to WPD series 101 within VCM series 95, 99 alternatives to 93
Index
capacity 31 static efficiency 93 VCM 2 (one-way-flow/end ramps) 94, 95 as alternative to FSD series 85, 89 to SD series 65, 67, 71, 73 to SLD series 57 within VCM series 93, 99 alternatives to 95 static efficiency 95 VCM 3 (two-way-flow/single ramp) 96, 97 as alternative 49, 55, 61, 77 alternatives to 97 static efficiency 97 VCM 4 (one- and two-way-flow/single ramp) 98, 99 as alternative 57, 61 alternatives to 99 static efficiency 99 vehicles see also standard design vehicles camper vans 6 four-wheel drive 6 limosines in multi-storey car parks 7 stretched 7 new registrations by type 203 sports utility 6 ventilation air change rates 192 fans 190, 191–2 natural 191 underground parking 190, 191–2 viewing panels, for disabled pedestrians 177 warped parking decks 91 see also WPD series washing-down facilities, decks 181 waterproofing decks 197–8 wheelbase, standard design vehicles 7, 10 widths aisles 10–11 minimum 13 parking stalls 9 stairs 155 standard design vehicles 6, 10 women-only car parks 170 WPD 1 (warped deck/one-way-flow) 100, 101 alternatives to 101 static efficiency 101
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