Narrow roadways
and bridges
Run-off-the-road crashes
and head-on collisions are frequently associated with narrow roads and bridges.
Such crashes are related to lack of maneuvering room because of narrow lanes and
shoulders and roadside hazards or curbing. Combine these factors with excessive
speed, and the results may be deadly.
Crashes
involving narrow bridges are not as frequent as roadway crashes but they are often
fatal. For both narrow roadways and bridges, crash rates may be lowered by increasing
lane and shoulder width or completely replacing the roadways and bridges. However,
replacing them may not be possible because of space or funding constraints. Below
are examples of how communities have developed low-cost ways to save lives.
The California Coalition cleans up "Blood Alley"
Overview
A 23-mile stretch of two-lane highway east
of Paso Robles, CA, is no longer considered a "death trap" by residents
of San Luis Obispo County. Formerly known as "Blood Alley," Highway
46 claimed 29 lives in 19 crashes over a five-year period. More than two-thirds
involved head-on collisions. Traffic on this major tourist artery included a high-speed
mix of commuters, truckers, and vacationers.
A
coalition of state, local, and private organizations devised a coordinated and
innovative approach to dramatically reduce deaths and injuries on this road. The
Coalition included the California Department of Transportation (CALTRANS), the
California Highway Patrol (CHP), the San Luis Obispo Council of Governments, and
the Fix 46 Committee of local businesses and residents. Because the state budget
would not allow Highway 46 to be widened, lower cost strategies had to be developed.
The CHP got approval from the state legislature to increase the number of patrols,
double the fines, and station a helicopter at the county airport to fly crash
victims to hospitals.
Additionally, more than a million
fliers were printed and disseminated to alert drivers of the dangers on this highway.
CALTRANS also developed an innovative "soft barrier" solution to Highway
46's head-on collisions and run-off-the-road crashes. It used a combination of
rumble strips, pavement reflectors, and raised thermoplastic striping placed along
the shoulders and the centerline. Such devices alerted motorists when they drifted
across the centerline or onto a shoulder.
Results
During
the 16 months before and after completion of the project, fatal crashes were reduced
from eight to zero; injury crashes were reduced by 14% and total collisions by
27%. CALTRANS is very pleased with the results and believes it represents the
best alternative short of widening a dangerous highway corridor like Highway 46.
Contact
Office of Public Affairs,
CALTRANS District 12, (805) 549-3281
Three strategies
for improving bridges
Narrow bridges are very expensive
to replace or widen. Communities may want to consider the following strategies
to lower bridge crash potential:
-
Bridge improvements.
These can involve improvements to the bridge structure and to potentially hazardous
bridge features, such as improving bridge rails and sidewalks, eliminating potholes
and poor skid resistance on the deck surface, and formulating better connections
between bridge abutments and guardrails.
-
Bridge
approach improvements. The safety of bridge guardrails and roadway approaches
can be improved by installing crash cushions, changing the location of guardrails,
and ensuring that guardrails on the approaching roads are appropriately attached
to bridge guardrails.
-
Operational improvements.
These include improved signs, pavement markings, and delineation in the bridge
approach area and on the bridge. They must be placed well in advance of the bridge
to alert drivers to potentially hazardous conditions.
