Highway Engineering

Example 2.7 Contd

2.8 A full example of the four-stage transportation modelling process,

2.8.1 Trip production

Assume a study area is divided into seven zones (A, B, C, D, E, F, G) as indi-

cated in Fig. 2.3. Transport planners wish to estimate the volume of car traffic

for each of the links within the network for ten years into the future (termed

the design year).

Using land use data compiled from the baseline year on the trips attracted to

and generated by each zone, together with information on the three main trip

generation factors for each of the seven zones:

36 Highway Engineering

1

4 5 6

2 3

1275 1450

1450 1025

325 1975 645

Figure 2.2Link volumes arising from ‘all-or-nothing’ traffic assignment procedure.

Destination zone

Origin zone 1 2 3 4 5 6

1 1-2 1-2-3 1-4 1-2-5 1-2-3-6

2 2-1 2-3 2-5-4 2-5 2-5-6

3 3-2-1 3-2 3-2-5-4 3-2-5 3-6

4 4-1 4-5-2 4-5-2-3 4-5 4-5-6

5 5-2-1 5-2 5-2-3 5-4 5-6

6 6-3-2-1 6-5-2 6-3 6-5-4 6-5

Table 2.14Minimum time/cost paths between zones in transport network

Destination zone

Origin zone 123456

1 250 100 125 150 75

2 300 275 200 400 150

3 150 325 100 100 240

4 200 150 50 350 125

5 100 300 125 250 200

6 150 150 180 225 175

Table 2.15Trip

interchanges between

the six zones