CHAPTER 5. SIMULATION RESULTS
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5.3.7 Platoon as good as request
For the lower traffic densities (map 0, 1, 2, 5, 6, 20, 21, 23) the best results are
given for θ = 5. For the higher traffic densities, higher values of θ are better. This
is because a higher θ will give priority to the traffic on the Wetstraat. The traffic
coming from the side-roads has to wait longer to get green compared with the traf-
fic coming from the Wetstraat. This implies that the green time on the Wetstraat is
longer than the green time on the side-roads, and the desired behaviour of traffic
lights is reached.
For the lower traffic densities (map 0, 1, 2, 5, 6, 20, 21, 23), the platoon
controller with minimal green time set to 1 second has the same results as the
request controller. For higher traffic densities, higher values for θ are better and
the results are again similar.
5.3.8 Optim (green wave) versus platoon
The green wave algorithm is a good algorithm which optimizes the traffic flow on
the Wetstraat. This gives good results, but the platoon controller has better results
for all traffic densities. For the traffic densities at 0, 1, 2, 5, 6, 20, 21, 23 hour,
platoon reduces the average total waiting time with 59-67%.
The simulation results show that the optim controller has a queue of 1186 road
users at the beginning of the Wetstraat at 7 o’clock (highest traffic density). For
the best result of the platoon controller (θ = 70, φmin = 1) there is a queue of 267
road users. This is a reduction of the queue with 77%.
5.3.9 Traffic density versus θ, growing as a monotonic func-
tion?
For the platoon controller with φmin set to 1, the best results are obtained with
θ = 5. With the higher traffic density, the best ATWT is for θ = 5, but this
gives unexpected side-effects and is not acceptable. This strange behaviour is
also shown in figure 5.28 on the next page. This figure does not show a gradual
transition in θ for the best results. It is possible that this gradual transition occurs
for a density between 4141 and 5270. This can be exploited in further research.