Highway Engineering

2.9 Concluding comments,

The process of traffic forecasting lies at the very basis of highway engineering.

Modelling transport demand is normally undertaken using a four-stage sequen-

tial process starting with trip generation and distribution, followed by modal

42 Highway Engineering

C

B

A D

E

F

G

Figure 2.3Zones and links in study area within worked example.

Figure 2.4Interzonal link flows for private vehicles (cars).

Network link Zone pairs contributing to flow along link Total link flow

A to B (A,B)(B,A) (A,D)(D,A) (A,E)(E,A) (A,F)(F,A) (A,G)(G,A) 16 683

A to C (A,C)(C,A) 2 352

B to C (B,C)(C,B) 7 098

B to D (A,D)(D,A) (A,F)(F,A) (B,D)(D,B) (B,F)(F,B) 16 592

B to E (A,E)(E,A) (A,G)(G,A) (B,E)(E,B) (B,G)(G,B) 9 362

C to D (C,D)(D,C) (C,E)(E,C) (C,G)(G,C) 5 798

C to F (C,F)(F,C) 1 882

D to E (C,E)(E,C) (C,G)(G,C) (D,E)(E,D) (D,G)(G,D) 12 944

D to F (A,F)(F,A) (B,F)(F,B) (D,F)(F,D) 9 667

E to F (E,F)(F,E) 2 701

E to G (A,G)(G,A) (B,G)(G,B) (C,G)(G,C) (D,G)(G,D) (E,G)(G,E) 8 334

F to G (F,G)(G,F) 6 238

Table 2.242-way vehicular flows along each link