Toll Facility Safety Study Report to Congress - About

Toll Facility Safety Study Report to Congress
Appendix D – Agency Site Visits
This section presents findings according to the following contributing factors that the study team
took note of during the site visits. Along with each contributing factor are strategies that the
various sites have implemented to address these challenges.
Merging / Lane Changing Behavior
Speeding
Driver Confusion and Distraction
Worker Exposure to Vehicles
Environmental Issues
Ergonomics
Assault
Note that much of the information presented here was also presented, together with a synthesis of
the interviews and the workshop, in Section 4, Findings – Factors Affecting Safety at Toll
Plazas.
Merging / Lane Changing Behavior
Toll plazas present unique challenges in terms of lane-changing behavior and merging. Many
plazas operate much like a complex intersection (i.e., there are on-ramps or off-ramps in close
proximity to the plaza, which creates excessive weaving maneuvers).
Speed variance between ETC and cash-paying customers is a challenge faced by all plazas
accepting both electronic and cash payment. Toll authorities across the country have tackled this
problem in a variety of ways. To start, many agencies make a standard practice of positioning
their ETC lanes to the left side of their plazas, with the idea that the faster-moving traffic will be
to the left side of the roadway. This practice appears to be effective except in situations where
there are on-ramps or off-ramps in close proximity to the plaza, in which case this practice
causes unnecessary weaving maneuvers. To combat this, many agencies have taken to
positioning dedicated-ETC lanes to both the left and right side of certain plazas.
Beyond this, some agencies have gone toward channelizing ETC traffic well in advance of the
plaza to reduce last-minute lane changes, and to channelize ETC traffic downstream of the plaza
to delay merging of traffic. Other agencies have begun adding a buffer lane between the ETC
lanes and cash or mixed-use lanes or to use physical separation (such as with a concrete barrier)
for the higher-speed traffic.
More common than physical separation, many agencies make use of delineators. However,
visibility can be an issue. To combat this problem, one agency replaced their solid white
delineators with wide yellow sergeant-striped delineators. Others have found that visibility was
improved after positioning the delineators in a “bowling pin” configuration instead of a straight
line. For those agencies that face an additional challenge in that their lane assignments change
throughout the day, pop-up delineators can be a good approach. However, some agencies in
colder climates have found that pop-up delineators do not perform so well during snow and icy
Appendix D – Agency Site Visits Page D-1