You are to determine the duration of the yellow light at a highway intersection. Assume that cars will be approaching the intersection traveling at 70 mph, and that the reaction time of the driver is 2.5 sec and that cars achieve a deceleration of 1/8 of the gravitational acceleration. if g=32.2 fps^2, a. how long must the traffic light remain yellow to allow drivers to come to stop before the traffic light turns red? b. what is the minimum distance of a car from the intersection when the lightturns yellow to ensure that it comes to a full stop before the intersection

You are to determine the duration of the yellow light at a highway intersection. Assume that cars will be approaching the intersection traveling at 70 mph, and that the reaction time of the driver is 2.5 sec and that cars achieve a deceleration of 1/8 of the gravitational acceleration. if g=32.2 fps^2, a. how long must the traffic light remain yellow to allow drivers to come to stop before the traffic light turns red? b. what is the minimum distance of a car from the intersection when the lightturns yellow to ensure that it comes to a full stop before the intersection

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

While travelling 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/s^2. It stopped 5 m from the block. Find the initial constant speed of the vehicles in kph, if the drivers perception reaction is 2.2 second
Problem: Car B is traveling a distance d ahead of car A. Both cars are traveling at 60 ft/s when the driver of B suddenly applies the brakes, causing his car to decelerate at 12 ft/s^2. It takes the driver of car A 0.75 s to react (this is the normal reaction time for drivers). When he applies his brakes, he decelerates at 20 ft/s^2. (Figure 1_ Question: Determine the minimum distance d between the cars so as to avoid a collision. Express your answer to three significant figures and include the appropriate units.
A car is traveling around a circular track of 660-ft radius. If the magnitude of its total acceleration is 6.2 ft/sec² at the instant when its speed is 32 mi/hr, determine the rate at at which the car is changing its speed. Answer: at = ± ft/sec²
A Circular Roadway and the Acceleration of Your Car "T (decreasing) (a) Constant angular speed (b) Decreasing angular speed Suppose you are driving a car in a counterclockwise direction on a circular road whose radius is r= 390 m (see Figure 8.20). You look at the speedometer and it reads a steady 32 m/s (about 72 mi/h). (a) What is the angular speed of the car? (b) Determine the acceleration (magnitude and direction) of the car. (c) To avoid a rear-end collision with a vehicle ahead, you apply the brakes and reduce your angular speed to 4.9 x 10-2 rad/s in a time of 4.0 s. What is the tangential acceleration (magnitude and direction) of the car?
Problem 2 A project by some to monitor the traffc safety at a busy intersection. They measwre (with a precision stopwatch) that exactly three seconds after car B passes through the intersection traveling south at vg = 55 mph, minivan A passes through at va = 70 mph on the road that runs at an angle 0 = 60° east of north. The speed of each automobile is Civil Engineering students requires them constant. Determine (a) the relative velocity (in mph) of B with respect to A, draw the vector triangles as part of your answer (b) the change in position (in fi) of B with respect to A during a 10-s interval, (c) the distance (in ft) between the two automobiles 3 s after A has passed through the intersection.
A high ratio power/mass ratio passenger car enters an acceleration lane at 45 kph and merges into traffic lane at 69 kph. Estimate the desired length of the acceleration lane when the acceleration rate is 4.3 m/s^2.
Two cars A and B are stopped at a traffic light, waiting for the light to change from red to green, see Figure 3. Car B is 6 meters behind car A. When the light turns green, car A starts accelerating at a rate of 0.3 m / sec2, while car B departs 2 seconds later and accelerates at a rate of 0.8 m / sec2. Determine the speed each car was carrying when they are side by side.
The acceleration of a vehicle takes the form: du/dt = 1.1 0.03u where u is the vehicle speed in m/s. The vehicle is traveling at 14m/s at time To Determine the following: 2.1. Time at which the vehicle attains a speed of 26 m/s 2.2. Acceleration of the vehicle after 3 seconds 2.3. Distance travelled by the vehicle when accelerated to a speed of 26 m/s
Problem#4: Calculate an object’s acceleration when ? = 100 ? and when ? = 175 ?. Refer to the v-s graph below. Problem#5: As a vehicle leaves the first point, it gains a speed at the rate of 4 ??/? 2 for 6 ? and then at the rate of 6 ??/? 2 until it has reached the speed of 48 ??/?. The vehicle maintains the same speed until it approaches the second point; brakes are then applied and the vehicle slows down constantly until it stops in 6 ?. The total running time from first point to second point is 40 ?. Plot the a−t, v−t, and x−t graphs, and calculate the distance between the first and second point.
Situation 1: Two automobiles A and B are approaching each other in adjacent highway lanes. At t = 0 seconds, A and B are 1 km apart, their speeds are VA = 110 kph and VB = 60 kph and they are at points P and Q respectively. Knowing that A passes point Q, 40 seconds after B was there and that B passes point P, 42 seconds after A was there. Question 6 Question 7 Question 8 Determine the time when they pass each other. Determine the speed of B when they pass each other. Determine the acceleration of A. 25.89 sec O 24,88 m/s O 0.139 m/s^2 O 20.89 sec O 25.12 m/s O -0.278 m/s^2 O 10.89 sec O 23.77 m/s O 0.34 m/s^2 15.89 sec O 22.54 m/s O 0.48 m/s^2
1. Assume you are observing traffic in a single lane of a highway at a specific location. You measure the average headway and average spacing of passing vehicles as 3 seconds and 150ft, respectively. What is the average speed of the traffic stream? Note: you can use two methods to conduct the calculation. 2. Assume the speed and density at a freeway location follows a linear relationship. You observe traffic flow rate of 2250 vehicles/hour at 45 mph and 3000 vehicles/hour at 30 mph. What are the jam density, free flow speed (max speed), and capacity of this freeway location? How about the density and speed (i.e., the critical density and the critical speed) at the capacity?
A car is stopped at an entrance ramp to a freeway; its driver is preparing to merge. At a certain moment while stopped, this driver observes a platoon of vehicles a distance x0 upstream and initiates the merge maneuver. The platoon approaches the entrance ramp at a constant speed v. The stopped car can accelerate from speed 0 to v at uniform acceleration rate a. Find the latest time at which the stopped car can safely start the merge maneuver; i.e., derive an expression for the “latest safe start time” in terms of the variables x0, v and a. Assume this latest time enables the platoon to maintain its constant speed and "just touch" the merging car's trajectory. Ignore the physical dimensions of the car.