Within-Day Replanning of Exceptional Events

Abstract

Typical software that is used for the simulation of traffic behavior focuses on scenarios that describe common situations like an ordinary working day without remarkable incidents. To simulate such scenarios, iterative approaches are used. They assume that the simulated people adapt to the results of the previous iterations. Such iterative approaches produce meaningful results for various scenarios as long as only typical, repetitive situations are modeled.However, a scenario may also contain incidents that occur by chance, which increases the complexity of a model substantially. In such scenarios, an iterative approach would produce illogical and even totally wrong results. An attempt to handle such scenarios is within-day replanning.This paper describes the problems that arise when applying an iterative simulation approach to a scenario with exceptional events. The within-day replanning technique is introduced and implemented in the multi-agent transport simulation framework MATSim. The implementation allows the simulated agents to replan the routes between their activities while they are traveling. By doing this, they can take the current traffic load into account, an important requirement for scenarios containing unpredictable incidents like road accidents.The capability of the implementation is demonstrated by conducting experiments with a scenario where the capacities of several arterial roads in the center of the City of Zurich are reduced due to an exceptional event. It is shown, that the agents that are affected by those events are able to reduce their travel times if they replan their routes using within-day replanning.

Agent-based model for continuous activity planning with an open planning horizon

“…For instance, Balmer limited the maximum simulation horizon of standard size scenarios to a single day, making it difficult to investigate effects occurring over a period of days or weeks. Another limitation of Balmer's model is that agents must commit to a specific day plan, making it challenging to simulate unexpected events realistically (Charypar et al 2009;Dobler et al 2012). Including such flexible behavior requires a different simulation approach that is capable of modeling demand continuously, i.e.…”

Location choice for a continuous simulation of long periods under changing conditions

“…For instance, Balmer (2007) limited the maximum simulation horizon of standard size scenarios to a single day, making it difficult to investigate effects occurring over a period of days or weeks. Another limitation of Balmer's model is that agents must commit to a specific day plan, making it challenging to simulate unexpected events realistically (Charypar et al (2009) ;Dobler et al (2012)). Including such flexible behavior requires a different simulation approach that is capable of modeling demand continuously over multiple days and weeks, i.e., agents should be able to make decisions about upcoming activities on-the-fly and with an open time horizon (see also empirical insights from the work of Doherty (2005)).…”

A scenario planning approach for disasters on Swiss road network

“…The purpose of the model is to simulate the vehicular traffic over large areas (countries or big cities) when the initial flux is almost negligible and the streets are empty [26]. This kind of scenario might occur at night when the population sleeps at home, and therefore, the vehicles are parked and the roads are free.…”

“…Bretschneider [23], Kimms et al [24] and Kim [25] suggest a heuristic approach to solve a model for large-scale networks for evacuation planning in urban areas. Dopler et al [26] introduced the within-day replanning technique which is useful to replan the routes between drivers while they are travelling, in particular, this study was realized for the city of Zurich considering the daily schedule of drivers (see Ref. 27).…”