Transportation – Problems (Week 4 & 5) (Transportation Exam Prep – Depth)
Mr. Mark T. Ingram, PE, PTOE Principal Director – Traffic Engineering / Transportation Planning Cobb Fendley and Associates, Inc. Email:
[email protected]
Licensed in Texas, Missouri, & Louisiana
1. The length of curve (in feet) when designing for rider comfort and using the following design parameters is most nearly? • Grade 1 = -2% • Grade 2 = +4% • Design Speed = 50 mph A) 574.2 B) 427.9 C) 322.6 D) 200.2
2. The average volume of traffic on the major street (total of both approaches) for 8 hours of an average day required to warrant the installation of an all-way stop controlled intersection is? (vph) A) 200 B) 300 C) 600 D) 1000
3. When designing a Crash Cushion at the end of a bridge rail, the Preferred Length (in feet) of the Crash Cushion reserve area when the design speed is 80 mph is most nearly? A) 70 B) 55 C) 35 D) 10
4. For a roadway curve with a posted speed of 40 mph and an advisory speed of 30 mph. The following sign should be installed: A) W1-1 WITHOUT a required advisory plaque (W13-1P).
B) W1-2 WITH a required advisory plaque (W13-1P).
C) W1-1 WITH a required advisory plaque (W13-1P).
D) None of the above. The W1-1 and W2-2 are not required in this situation. 5. Minimum inside turning radius for a Passenger Car Design Vehicle is most nearly? (feet) A) 14 B) 25 C) 21 D) 35
6. On a roadway with the posted speed of 45 mph, the placement of the stop ahead warning sign for an approaching intersection with stop control is most nearly? (feet)
A) 100 B) 125 C) 175 D) 775 7. The LOS for the following two lane highway is most nearly? • Class I • Average Travel Speed = 43 mph • Percent Time Spent Following = 68.5% A) F B) C C) E D) D
8. The Control Delay at a two-way stop controlled intersection is 22.5 seconds per pedestrian. The LOS at the two way stop controlled intersection for pedestrian mode is most nearly? A) A B) D C) E D) C
ANSWERS
1. Page 3-160 of the AASHTO (A Policy on Geometric Design of Highways and Streets). When designing for passenger comfort use equation 3-51.
AV 2 L= 46.5 Where: L = Length of sag vertical curve in feet. A = Algebraic Difference in Grade = |G2 – G1| = |4 – (-2)| = 6 V = Design Speed in mph
AV 2 6 × (50) 2 = L = = 322.58 feet 46.5 46.5 2. Page 52 of the Manual on Uniform Traffic Control Devices Section 2B.07 Multi-way Stop Applications. Under Guidance: Section C. Minimum Volumes: The vehicular volume entering the intersection from the major street approaches (total of both approaches) averages at least 300 vehicles per hour for any 8 hours of an average day. Answer is B) 300
3. Preferred length of the crash cushion reserve area is found in the AASHTO Roadside Design Guide, page 8-46, Table 8-11 Design Speed is 80 mph. Answer is 70 feet. The answer is A) 70 feet
Reference: AASHTO Roadside Design Guide, Washington DC, 2011
4. Page 110 of the Manual on Uniform Traffic Control Devices. Section 2C.07 Horizontal Alignment Signs (W1-1 through W1-5). See Table 2C-5 first and determine if the sign and plaque are required.
Difference between the posted speed and the advisory speed is 10 mph. The sign is required and the plaque is required. Next. Determine if the W1-1 or the W1-2 is the proper sign for this condition. Page 110 of the Manual on Uniform Traffic Control Devices. Section 2C.07. Standard: Second Paragraph A turn (W1-1) sign shall be sued instead of a Curve Sign (W1-2) in advance of curves that have advisory speeds of 30 mph or less. The advisory speed is 30 mph in this problem statement. The answer is C) W1-1 WITH an advisory plaque (W13-1P).
5. Minimum inside turning radius for a Passenger Car Design Vehicle is most nearly? (feet) AASHTO “Green Book” (i.e. A Policy on Geometric Design of Highways and Streets). Page 2-10. Figure 2-1 Minimum turning Path for Passenger Car (P) Design Vehicle. Answer 14.4 feet on the inside of the curve. Answer is most nearly A) 15 feet
6. Page 108 of the Manual on Uniform Traffic Control Devices Table 2C-4
Posted speed = 45 mph Stop Condition (Deceleration to the listed advisory speed of 0 mph for a stop condition. Answer = 175 feet. Answer is C) 175
7. Go to page 15-7 Automobile LOS for Two-Lane Highways.
Highway Capacity Manual, Transportation Research Board – National Research Council, Washington, DC. Class I ATS = 43 mph = LOS C PTSF = 68.5% = LOS D Two LOS designations obtained. Page 15-27 of the HCM states that… For Class I highways, two service measures are applied. When two LOS designations are obtained the worse of the two is the prevailing LOS. Answer: LOS D Answer is D) LOS D
8. Chapter 19 of the Highway Capacity Manual (Two Way Stop Controlled Intersections). Page 19-2 (Exhibit 19-2) LOS Criteria (Pedestrian Mode)
Highway Capacity Manual, Transportation Research Board – National Research Council, Washington, DC. Control Delay = 22.5 seconds per pedestrian. Answer = LOS D Answer B) LOS D
