TRANSPORTATION AND MISCELLANEOUS

1. A horizontal compound curve connects two tangents as shown below. The bearing of the back tangent is N46°25'32" E, and the bearing of the forward tangent is $17°56'21" E. The curve radii to be used are R1 = 1,800 ft. and R2 = 900 ft. The PC is located at station 138+34.12 and the Plat station 158+ 12.98. The station of the PCC is most nearly.

• 145+12.54

• 147+05.23

• 148+50.61

• 151+03.32

A parabolic crest curve is followed by a sag curve. The two curves are connected by a tangent section, as shown. A bridge structure is located at station 45+55.00. The elevation of the low point on the bridge is 405.54 ft. The design speed (mph) of a truck (assume driver's eye elevation = 7.6 ft.), based on adequate sight distance under the bridge overpass on curve number 2, is most nearly.

• 65

• 75

• 80

• 85

3. A circular horizontal curve connects two tangents with a deflection angle of 42°50'. The roadway is a two-lane highway with 12-ft lanes. The centerline of the roadway has a radius of 1,245 ft. The design speed = 50 mph. PC for the centerline circular curve is at sta. 23 + 32.56. It is proposed to insert a pair of symmetric spirals at the PC and the PT. The minimum length of spiral (ft.) is most nearly.

• 120

• 140

• 160

• 180

• 110

• 130

• 150

• 170

• 9x10^6

• 15x10^6

• 20x10^6

• 23x10^6

A 6-lane highway has the following characteristics: Level terrain 8. What is the recommended length of cycle for a 4-phase signal with 3-sec lost time per phase, with the following critical movements?

Lane width=11-ft lanes

Average spacing between accessing driveways = 600 ft.

Right shoulder width = 6 ft.

Clear distance to nearest obstruction in median = 4 ft

Directional hourly volume = 3,440 veh/hr.

The traffic stream includes 8% trucks, 3% buses, and 2% RVs.

Peak hour factor, based on 15-min traffic counts, is 0.88.

Drivers are mostly commuters.

The LOS for the peak direction of the highway is most nearly:

• B

• C

• D

• F

• 86+50

• 87+25

• 88+00

• 88+50

• 105 sec

• 125 sec

• 140 sec

• 160 sec

• 3.7

• 3.8

• 3.9

• 4.1

• 14

• 15

• 16

• 17