NYMTC Regional Pedestrian Safety Study - New York Metropolitan ...

Speed management through engineering measures is probably the single most effective way to
increase safety for all modes. Fatalities increase exponentially with speed. Speed-related factors
that affect pedestrian safety include impact speed, stopping distance, and driver’s narrowing field
of vision. A policy change or a change in a design standard that leads to fewer pedestrian
crashes may not cost anything. For example, almost all Seattle arterial streets are designed to a
48 km/h (30 mi/h) design speed, which is the legal speed limit unless otherwise posted. This is
one of the reasons Seattle has one of the lowest pedestrian fatality rates in the nation; Seattle has
made a commitment to safety as the number one priority.
In this section, three miscellaneous approaches to reducing speed will be discussed, followed by
a longer section on traffic calming.
Approaches to Reducing Speed
Reduced Speed Zones: The use of reduced speed zones in areas with a large number of
vulnerable pedestrians is an old practice for school zones. NYCDOT has a demonstration
project involving 10 schools to test 20 mph and 15 mph zones near schools. A similar concept
could be considered for senior zones, in areas where a large number of seniors walk. Such senior
zones could involve other modifications, such as increased crossing times at signalized
intersections. However, the walking patterns and locations of seniors are different from those of
children; while children can be expected to walk in the vicinity of schools during school hours,
seniors walking patterns are more diffuse and not confined to specific areas or times. NYCDOT
policy is to examine conditions on a site-by-site basis and implement special treatments for
seniors when found appropriate. Thus, if a higher proportion of seniors are found in a location,
the signal timing will be adjusted to better meet their needs. However, NYCDOT’s policy is to
not demark senior zones.
If a reduced speed zone is implemented, the driver should be alerted through traffic calming
methods and/or by flashing beacons. In cases where the reduced speed zone applies during
specific times, such as school zones, the flashing beacons should be activated only during those
times. As noted above, in order to be effective, the reduced speed zone should be reinforced by
engineering measures, such as traffic calming.
Speed Monitoring Displays (SMD): An SMD is a speed monitoring radar combined with an
LED sign that informs approaching drivers at what speed they are traveling. Typically the speed
limit is also included. A Utah study (Saito, 2005) found that they reduced both average speeds
and the percent of vehicles over the speed limit in school zones. A similar study of their use in
work zones found that they reduced speeds by six percent (about four mph); they were most
effective in the first week after implementation (Saito, 2003).
Curve Radius: One common pedestrian crash type involves the right turning vehicle at an
intersection. The concept of a reduced radius is simple and basic - control speed through
geometry. Instead of accommodating the vehicle with a large sweeping turn, a tighter radius will
force the driver to negotiate the turn at a slower speed and with increased reaction time. There
are also the added benefits of a shorter pedestrian crossing distance and more sidewalk area. The
turn radius should be designed within the context of the turning area, whether it needs to
NYMTC Pedestrian Safety Study 63