Data obtained from aerial photography showed nine vehicles on a 720 ft-long section of road. Traffic data collected at the same time indicated an average time headway of 4.2 sec (a) the density on the highway (in veh/mi) veh/mi (b) the flow on the road (in veh/h) veh/h (c) the space mean speed (in mi/h) mi/h

A section of a highway is known to have a free-flow speed of 65 mi/h and a capacity of 3500veh/h. In a given hour, 2500 vehicles were counted at a specified point along this highway section. If the linear speed-density relationship applies. What would be the jam density (veh/mi)? choices 212.72,210.64,215.38,216.90

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