6. Using the measured time headway distributions for the traffic flow level of 15-19 vehicles per minute, apply one of the following mathematical distributions and prepare a table simi- lar to Table 2.4 and plot on a figure similar to Figure 2.7. (a) Shifted negative exponential distribution (a = 0.5 second) (b) Erlang distribution (K = 2) (c) Gamma distribution (K = ) Compare results with the measured and Pearson type III distributions shown in Figure 2.7. = Headway (sec) 4 6 8 10 2 5 Measured time headway distributions Pearson type III time headway distributions 10 200066 AM 15 299 & XXX Minute flow rate (veh/min) 20 2003 2002 25 2000 DO 30 Figure 2.7 Pearson Type III Time Headway Distributions (based on measured head- way distribution data presented in Figure 2.2) TABLE 2.4 Pearson Type III Time Headway Distribution Calculations Probability, I-a 2(t-a) acr- a) K-1 -1/1-a P(tsh