A freeway has the following relationship: S = 75.4e-bD where S is in mph, for D is inpc/mi/ln (D<145), b is a positive constant in In-mi/pc. What is the free-flow speed S, in mph?Write the expression of V = f(D). Leave b in the equation. If the capacity Vm = 2500 pc/h/Inhappens at Do = 45 pc/mi/ln, what is the value of b?

A freeway has the following relationship: S = 75.4e- where S' is in mph, for D pc/mi/ln (D<145), b is a positive constant in In-mi/pc. What is the free-flow speed Sf in mph? Write the expression of V = f(D). Leave b in the equation. If the capacity Vm = 2500 pc/h/ln happens at Do 45 pc/mi/ln, what is the value of b? =

A freeway has the following relationship: S = 75.4e- where S' is in mph, for D pc/mi/ln (D<145), b is a positive constant in In-mi/pc. What is the free-flow speed Sf in mph? Write the expression of V = f(D). Leave b in the equation. If the capacity Vm = 2500 pc/h/ln happens at Do 45 pc/mi/ln, what is the value of b? =

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter3: Characteristics Of The Driver, The Pedestrian, The Bicyclist, The Vehicle, and The Road

Section: Chapter Questions

Problem 10P

See similar textbooks

Similar questions

A section of highway has a speed–flow relationship of the form q = au2 + bu, where q is the traffic flow in veh/h, u is the space-mean speed of traffic in mi/h, and a and b are unknown parameters. It is known that at capacity (which is 3100 veh/h) the spacemean speed of traffic is 28 mi/h. Determine the speed when the flow is 1500 veh/h and the free-flow speed.
A section of highway has a speed-flow relationship of the form q = a*u*u + b*u (a and b are coefficients to be determined). It is known that at capacity (which is 3100 veh/h) the space-mean speed of traffic is 35 km/h. Determine the speed when the flow is 1500 veh/h and the free-flow speed.
Determine the maximum flow for a section of road with the relationship given as u= 53-0.43k where u is speed in kmph and k is the density in vehicle/km
The spacing of the cars moving along the same lane of an expressway is 40 m center to center. If the average velocity of the car is 60 kph, determine the volume of traffic in veh/hr.
On a road, the speed - density relationship of a traffic stream is given by u = 70 - 0.7 k (where speed, u, is in km/h and density, k, is in veh/km). At the capacity condition, the average time headway will be
13.How much horsepower must be delivered to the wheels of a 10,000 lb loaded truck to maintain a constant speed of 55 mph on a +5% grade? Assume the following: Aerodynamic drag coefficient = 0.4 Vehicle’s frontal cross-sectional area = 100 ft2
While traveling at a constant speed a driver saw a road block 112 m away. He applied the brakes and the car decelerated uniformly at 6.4 m/s2. It stopped 5 m from the block. The driver’s PRT is 2.2 seconds. Sketch and calculate the initial constant speed of the vehicle in kph if;a. The roadway is levelb. The roadway grade is +10%c. The roadway grade is -10%
A Greenberg’s model was developed based on data collected from a roadway. The following values are given: Dj = 130 veh/mi; D = 30 veh/mi when S = 30 mi/h. Find the maximum flow for this traffic stream (vmax)
Assume that drivers in fact follow the rule of the road of keeping .a gap of one car length (L) for each 10-mi/h increment of speed. Assuming a car length of 20ft, develop the equations of stream now and draw the u-k, q-u, and q-k diagrams.
2. A highway is having a design speed of 65 km/h and its pavement is having a friction coefficient of 0.4. If the reaction time of drivers is taken as 2.5 sec and average length of vehicles as 5 m, determine the capacity of the highway.
The average spacing of the cars moving along the same lane of an expressway is 54.3 m center to center. Determine the volume of traffic in veh/hr if the average velocity of the cars is 51 kph.
The rate flow at a point in the highway is 1200 vehicles/hour. Find the space mean speed in mph if the density of traffic is 25 vehicles per mile