Question

The fgure below depicts the space-time diagram for vehicles travelling at constant speeds on a single-lane road section. A detector is located at the beginning of the section to measure the traffic stream characteristics of the road During a period of 15 seconds, four vehicles pass over a detection zone with the speeds of 18 km/h, 27 ㎞h 36 km h and 27 kmh for Vehicles 1.2.3 and 4 respectively The times at which each vehicle enters and exits the detection zone are shown on the horizontal axis. Detection zone What is the occupancy of the road section during the observation period of 15 seconds, based on the data collected from the detection zone? a 0.112 b. 0.182 O c. 0283 o d 0 353 e 0.470 QUESTION 17 For the figure and description provided in Q 16 above, what is the average spacing of the four vehicles at Time-15 seconds? O a 9.5m O b. 10.8 m . 12.5 m O d 13.4 m 15.0 m QUESTION 18 For the figure and description provided in Q16 above, what is the length of Vehicle 1 if the length of the detection zone is 2m? Da, 4.5 m Ос. 55 m O 6.5 nm

Answer 1

16) Occupancy by first vehicle--- Occupancy by Second vehicle 0.06667 Occupancy by third vehicle- 0.10 1515 15 10.75-10 .75 15 0.05 15 Occupancy by fourth vehicle (15-1.5)x5-67.5m Total occupancy 0.1+0.06667 +0.05+0.06667 0.283340.283(option C) 17) Speed of first vehicle 18km/h-18x -5m s Distance travelled = (15-15)×5= 67.5m Speed of Second vehicle-27km / h = 27 x--= 7.5m / s Distance travelled - (15-7)x7.5 60m Speed of third vehicle- 36km / h -36x^10m/s 18 Distance travelled (15-10)x10 50m Speed of fourth vehicle-27km / h = 27x-= 7.5m / s Distance travelled (15-12)x7.5 22.5m (67.5-60)+(60-50)+(50-22.5) 45 Therefore average Spacing Option E is correct 18) Length of detection zone -2nm Speed of first vehicle-5m/s Distance travelled in detention zone- 5(3-1.5)-7.5m Length of vehicle one -7.5-2-5.5m option C is correct 15m