Table 92 to Table 95 show an example in which link impedance consists of the current travel time and road toll. For HGV transport systems which have a higher "value of time" the influence of road tolls on link impedance is less than for car transport systems.
|
Link length |
10,000 m |
|
Permitted maximum speed v0 car |
130 km/h |
|
Permitted maximum speed v0 HGV |
100 km/h |
|
Road toll for cars |
€1 |
|
Road toll for HGV |
€5 |
|
Capacity |
3,000 car units/h |
|
Car volume |
1,000 cars/h = 1,000 car units/h |
|
HGV volume |
100 HGV/h = 200 car units/h |
|
Value of time VOTCar |
18 €/h = 0.005 €/s |
|
Value of time VOTHGV |
36 €/h = 0.010 €/s |
|
VD function according to BPR |
with a = 1, b = 2, c = 1 |
|
Car travel time in unloaded network |
t0 car = 10 000 • 3.6 / 130 = 277s |
|
Car travel time in loaded network |
tCur car = 277 • (1+(1 200/3 000)²) = 321s |
|
Car speed in loaded network |
vCur car = 10 000 • 3.6 / 321 = 112 km/h |
|
HGV travel time in unloaded network |
t0 HGV = 10 000 • 3.6 / 100 = 360s |
|
HGV travel time in loaded network |
tCur HGV = MAX (321s; 360s) = 360s |
|
HGV speed in loaded network |
vCur HGV = 100 km/h |
|
HGV speed only declines if the volume is more than 1644 car units/h if: tCur = 277 • (1+(1644/3000)²) = 360s |
|
|
Car impedance in loaded network |
Rcar = 1 + 0.005 • 321 = 2.61 € |
|
HGV impedance in loaded network |
RHGV = 5 + 0.010 • 360 = 8.60 € |
