Problem 2 Speed data collected on an urban roadway yielded a standard deviation in speeds of ± 5.1 mi/h.

3. A driver takes 3.5 s to react to a complex situation. How far does the vehicle travel before the driver initiates a physical response to the situation (i.e., putting his or her foot on the brake)? Plot the results for speeds ranging from 30 to 70 mi/h (in 5-mi/h increments).

(a) How fast does the end of the stopped queue move upstream? (b) When is the queue cleared? (c Did the first vehicle not in the queue pass the intersection (the stop bar) in this green time window (show how you get your answer)? (d) What is the delay to the 3rd vehicle to join the queue? (e) What is the delay to all the vehicles arrived in one cycle?

In the above problem, suppose that there is an initial queue in NB that with jam density of n vehicles at the start of the NB green, and no vehicles arrive to join the queue during the green time window. What is the maximum n such that the last vehicle in the queue can cross the stop bar just before NB yellow starts (we consider the vehicle crossed the stop bar once its rear crossed it)? [Remark: draw the wave lines and vehicle trajectories will help you solve the problem]

(f) Draw all the shock waves on a time-space diagram, and compute their speeds (g) What is the travel speed of vehicles inside the queue formed behind the bottleneck? (h) What is the furthest point the congestion (queue) has reached upstream? (i) When is the congestion dissolved? (j) How many vehicles are being delayed during this morning commute?

DESIGN OF STEEL TRUSS BRIDGE Design scenario: Due to the logistic needs for one of the residential areas in the city, the state department of transportation announced a notice to bidders for the construction of a bridge to carry a centered highway across a valley (see figure 1 for the site configuration). In this notice, the state department of transportation highlighted the following: • The designed bridge should be able to carry its own weight (to include the weight of the reinforced concrete deck), plus the weight of a truck loading equivalent to 350kN. • The state department will only consider designs with a total cost less than 480,000 $. The design cost should include the cost of material, connection, product, and site. • The designed bridge should be a standard abutment bridge • One cable anchorage is allowed. • A medium-strength concrete should be used for the bridge deck. The aim of this project is to: • Analyze and design trusses and frames manually and using engineering software • Apply the basic concepts of mechanics to find solution of practical problems • Develop a systematic approach to problem-solving skills • Construct free-body diagrams • Basic definitions of stress stain, Stress due to axial loading • Work in diverse teams

3. (10 points) Please read the readings and answer the following questions: a. Can we always improve the traffic conditions by building extra roads in our traffic network? Circle your answer. TRUE or FALSE b. Why did New York City decide to close the 42d Street?

Due to improvements in highway ITS assets, the average truck operating speed on a certain interstate freeway increased from 57 to 62 mph. Find the decrease in shipping inventory costs per year for trucks that comprise 30% of the overall traffic stream of 75,500 vpd. On the average, each truck hauls an average of $2.2 million worth of goods daily. Assume an 7% interest rate

The injury crash rate with and without improvement project at a rural two-lane highway is 2.87 and 3.5 per million VMT. Determine the user safety benefit in monetary terms due to reduction in crash rate. Assume average vehicle occupancy=1 and annual VMT is 1.5 and 1.8 millions for before and after improvement scenarios. Unit Cost of incapacitating Injury = 181,276 (2005 $).

Traffic for a future roadway is projected to be AADT = 15000 vehicles. Vehicle distribution and thecorresponding ESAL factors are given in Table 1. 1. Using a growth factor of 3%, estimate traffic in the design lane, in ESALS, for a design life of 30years. 2. The subgrade soil is a high plasticity clay (CH). The available base and sub base materials have R-Values of 75 and 50, respectively. Design a conventional flexible pavement structure using the 1 993 AASH TO method. Clearly state all assumptions made.