The pre-signal is an additional traffic light (i.e. stop line) upstream of the main coordinated intersection that separates directional traffic flows upfront. The pre-signal allows vehicles with the same direction to proceed and the vehicles will utilize the entire cross-section of the main intersection while discharging the main intersection during its green phase. Pre-signals can yield a higher intersection capacity. However, behavioral assumptions in those studies regarding the spread behavior of drivers in the sorted area were not based on validated findings from behavioral science. Therefore, this research tries to investigate the spread behavior of drivers, with the objective of reflecting these findings against potential implications for the applicability and efficiency of pre-signals for regular traffic.
To gain insight in the spread behavior of drivers and their underlying choice strategy, a stated-choice experiment has been executed in which respondents were repeatedly asked to state their preferred lane choice. Respondents were exposed to a variety of traffic situations, which varied in traffic crowdedness, turning directions, and number of spread opportunities. This was done using videos and static images from the driver’s perspective, which were extracted from a 3D visualization model. Results showed that in general, drivers account for heavy good vehicles more than twice as heavily than for cars. Besides that, the discomfort for heavy good vehicles increases whenever it concerns the trailing vehicle, and when these vehicles are positioned in lanes closer to the driver. Also, substantiation differences have been found in the discomfort associated with lane changing. Concerning equal spread, only three out of the ten choice scenarios contributed to an equal spread in the sorted area. The underlying reason for the success of these choice scenarios was the absence of multiple lane changes to reach the outer lanes of the sorted area.