On the two lane carriageways, roadworks restrict the width of both
traffic lanes, generating a bottleneck to the traffic flow. the
maximum flow per lane on the unobstructed carriageway is
2100 vehicles per
hour whilst on the section under repairing the maximum flow
per lane reduces to 1200
vehicles per hour. when stationary, vehicles are spaced at
average distance headway of 6 m. it may be assumed that
there is a linear relationship between speed and density. when the
traffic flow approaching the roadworks is 3500 vehicles per hour,
calculate:
1the speed of the traffic system a considerable distance in advance
of the bottleneck;
2the speed of the traffic stream immediately before the
commencement of the bottleneck; and
3the speed of the shockwave foamed by the bottleneck.