Potential Impact Of Advanced Traveler Information Systems (Atis) On Accident Rates In An Urban Transportation Network

Advanced Traveler Information Systems (ATIS) have the potential to improve the travel experience of individuals and, consequently, enhance the transportation system performance. ATIS will provide information that assists the traveler in selecting his destination, departure time, pre-trip route, enroute diversion, and trip chaining. One of the direct benefits of ATIS is to provide warnings on incident blockages which may encourage drivers to divert from incident routes, leading to shorter queues, fewer abrupt deceleration and safer travel conditions. ATIS may have various safety implications on the transportation network. On one side, there exists the possible distracting effect of the on-board gadget on the driver. This research is still under investigation. On the other side, congestion avoidance may improve traffic safety on the network. Thus, reducing congestion on freeways by diverting traffic to alternative arterials is expected to reduce the accident risk on freeways. However, safety on these arterials may be reduced as they become more congested. Moreover, travel conditions on arterials are not as safe as on freeways because of the higher level of traffic flow interruptions caused by side streets and traffic signals. In essence, when traffic is diverted from congested freeways to less congested arterials, the switch from higher to lower roadway hierarchy may offset the safety benefits anticipated on freeways. This paper presents a methodology for predicting changes in accident rates as a result of traffic diversion by ATIS in Orlando\u27s Transportation Network