Geoscience Reference
In-Depth Information
Table 21.1
Results of dispersion of 20 % of CBD trips to other areas
Percentage change
of total VKT (%)
Percentage change
of total VHT (%)
Super zone origin
Tel-Aviv city (CBD)
10.11
1.73
Inner ring
North
0.89
0.23
Center
2.31
0.68
South
0.44
0.61
Middle ring
North
2.32
1.26
Center
1.84
0.33
South
2.73
0.46
Outer ring
North
4.17
3.66
Center
3.40
0.63
South
4.85
0.39
Total
5.55
3.49
available; further, the majority of trips entering the area in this period are made by
commuters.
As also discussed in the methodology section, we assumed that the total demand
for car trips was fixed. Therefore, the 20 % of trips with a destination within the
CBD that had been reduced were assumed to be diverted proportionally across the
metropolitan area. This proportional dispersion would mainly increase trips to
fringe areas of the CBD. The result of this process is a modified origin-destination
matrix, which was assigned to the same road network as in the base case.
The link flow results of the traffic-assignment model were aggregated for each
super-zone origin in the TAMA. The following variables were examined for each
super zone: total vehicle kilometers traveled (VKT) and total vehicle hours traveled
(VHT). Table
21.1
shows the results of this policy scenario, compared to the base
case.
As expected, both VKT and VHT decrease to the greatest extent in the city of
Tel-Aviv. The values of these variables decrease less intensely in the inner-ring
super zones. This result is explained by the spatial distribution of the trips on the
network, since trips originating in other areas have to pass through one of these
areas in order to arrive at the CBD. Thus reducing parking supply in the CBD
influences not only the CBD but also the fringe areas.
In contrast to the CBD and the inner ring, the middle and outer rings showed
increased VHT and VKT This, too, is accounted for by the effect of trip
re-distribution on the transportation network of the Tel Aviv area. Since the
diverted trips were proportionally dispersed across the TAMA, most trips
originating in the outer-ring zones still have to travel to fringe areas, increasing
the total VKT. Therefore, an increase in the number of trips in the fringe areas has a
negative impact, since in this case vehicles have to travel farther from the origin in
order to reach their destinations.
The conclusion of this analysis with respect to trip distribution is that depending
on the spatial distribution of trips during the morning peak hour, the dispersal may