The growth in electronic toll collection (ETC) transactions at toll plazas in this country has resulted in an increase of speed differentials within the plaza approach and departure areas. In addition, since the operational characteristics of ETC technology are vastly different than traditional cash collection (e.g., manual and automatic) the toll road operator must configure the plaza to maximize safety and efficiency so the user can quickly unravel the added complexities. This complexity breeds increased driver confusion and erratic maneuvers within a plaza. These conditions combine to result in a reduction in safety with a coincident effect on operational performance.
Historically, toll plazas have been prone to sudden stops and lane changes as well as unsafe approach and departure speeds, particularly in an environment of merging and queuing vehicles that effectively increases the probability of a collision. With just two methods of collection, manual and exact change automatic coin machines (ACM), problems still pervade toll plazas with incorrect lane selection and the resulting unsafe stops and maneuvers to change lanes. The addition of ETC in manual and ACM lanes tends to increase this confusion. When ETC dedicated lanes are deployed in conjunction with these conventional lane types, differential speed and driver expectations for high speed, non-stop performance compounds the problems encountered in manual and automatic lanes.
Toll plazas with express lanes typically separate ETC customers from the conventional plaza upstream of the plaza, and either use the continuation of the mainline lanes or channelize the ETC customers into non-stop express lanes that diverge from the mainline lanes using an AASHTO compliant alignment. Dedicated ETC lane plazas (where a non-stop dedicated ETC lane is provided in the conventional plaza) present special challenges due to the mixing of non-stop vehicles and cash customers who are required to stop to pay tolls at the plaza. The diverging, weaving and merging both upstream and downstream of conventional toll plaza can be minimized significantly through the use of advance signing, provided lanes serving each payment type are grouped together. Conventional plazas with ETC dedicated lanes that vary the location (grouped to the far left, far right, and center, or alternated ETC dedicated and cash lanes) among plazas are inherently difficult to sign as well as engender a “user familiarity” in advance of the plaza.
The following sections deal individually with the following issues:
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