
The initial blip in speed of the following vehicle (see Figure 5.45) is due to the excessive gap g
that results whenever the following vehicle is moving at very low speeds. The car-following model,
Equation 5.62, implemented in the M-file ‘‘acc.m’’ is not robust, that is, it is not valid at following
vehicle speeds close to zero, which occurs when the simulation begins. Similar artifacts are present
in the gap (Figure 5.46) and acceleration (Figure 5.48) plots. One of the exercise problems addresses
this point further.
0 102030405060708090
0
0.3
0.6
0.9
1.2
1.5
g, G(s)
1.8
2.1
2.4
2.7
3
Actual and desired gap vs. time
Time (s)
Actual gap
Desired gap
FIGURE 5.46 Desired ...