Consider the problem of traffic flow on a three-lane (one direction) freeway which can be described by the Greenshields model. One lane of the three lanes on a section of this freeway will have to be closed to undertake an emergency bridge repair that is expected to take several hours. It is estimated that the capacity at the work zone will be reduced by 28 percent of that of the section just upstream of the work zone. The mean free flow speed of the highway is 60 mi/h and the jam density is 140 veh/mi/ln. It is estimated that the demand flow on the highway during the emergency repairs is 86 percent of the capacity. Using the deterministic approach, determine the following for the expected repair periods of 1 h,1.5 h,2.5 h,2.75 h, and 3 h. (a) the maximum queue length (in veh) that will be formed (b) the total delay (in h) (c) the number of vehicles that will be affected by the incident (d) the average individual delay (in min) (e) Plot a graph of average individual delay versus the repair period. (f)

The average daily traffic on a stretch of road is 300 commercial vehicles per lane per day. Design traffic repetitions for 10 years when vehicle damage factor is 2.5 and traffic growth rate is 7% is

The traffic demand for a six-lane urban arterial road (three lanes per direction) is given in the table below. The relationship between flow and density for this road follows GreenShiled's model, with a free flow speed of 105 km/h and a jam density of 92 veh/km/lane. Two of the three lanes of the EB direction were closed at 5:00 AM for maintenance. The two lanes were re-opened at 8:00 AM, allowing the traffic to be released at capacity conditions. a) What is the maximum length of the queue upstream of the bottleneck? b) At what time the queue upstream of the bottleneck will be fully dissipated? c) What is the furthest point upstream of the bottleneck that will be impacted by the lane closure? d) Draw the shock wave diagram showing shock wave speeds, critical times, and distances. Time 5:00 6:00 AM 6:00 7:00 AM 7:00 8:00 AM 8:00 9:00 AM 9:00 10:00 AM 10:00 11:00 AM Demand (vph) 2000 4000 6400 6000 3600 3000

A long segment of suburban freeway is to be designed on level terrain. The level segment, however, is followed by a 4.5% grade, 2.0 miles in length. If the DDHV is 2,500 vehicles per hour with 15% trucks (standard mix), how many lanes will be needed on the (A.) Upgrade, (B.) Downgrade, (C.) Level terrain segment to provide for level of service C? Lane widths and lateral clearances may be assumed to be 12 feet and 6 feet, respectively. Ramp density is expected to be 1.0 ramps per mile. The PHF is 0.92. Good weather, no incidents, no work zones, and regular users of the facility may be assumed.