METRORail Traffic Safety Assessment
Executive Summary
Concern over motor vehicle
collisions with METRORail light rail vehicles during the first month of rail
service led to
METRO requesting the assistance of the Texas Transportation
Institute for an analysis of the safety of the rail line.
This assessment found
that the METRORail design was consistent with the provisions contained in the
Manual of
Uniform Traffic Control Devices (MUTCD) and general design practice
involving traffic safety provisions in constrained
alignments.
A research team
consisting of experts from TTI and the light rail industry examined data on
METRORail's design and operations, on the collisions, and on similar experiences
of other light rail systems. The work was initiated in early February and
included a review of collisions through that time. The research team also spent
three days in Houston to observe the conditions along the rail right-of-way,
particularly at locations where rail vehicles and motor vehicles interface. This
report summarizes the findings of the assessment.
Background Information
The
first 7.5 miles of METRORail was constructed to fulfill part of Houston's
long-range transportation plan, and provides for high-capacity transit service
in the travel corridor linking the downtown area with Midtown, the Museum
District, the Texas Medical Center, and the Reliant Park area. The rail line
travels at grade along the surrounding streets, to the left or right of the
roadway in some areas and in the street median in others. For most of the rail
line, the motor vehicle lanes and METRORail trackway do not overlap, but do
interface at intersections; however, in the Texas Medical Center area, left-turn
lanes "share space" on the trackway.
Collisions
The most common type of
collisions that occurred between motor vehicles and METRORail vehicles through
the first month involved illegal left-hand turns by motorists. Despite traffic
signs and signals designed to control the location and timing of left-turn
movements along the rail line, several motorists have turned into or in front of
oncoming LRVs, sometimes turning from an incorrect lane. All collisions examined
appeared to have been due to improper or illegal turns or other driver errors.
Illegal left turns are a primary source of motorist-LRV collisions in other
light rail systems as well: light rail lines in Los Angeles, San Diego,
Portland, Dallas, and Salt Lake City have employed a variety of design features
and public education programs in their efforts to reduce unsafe movements by
drivers along the rail right-of-way, with varying degrees of success. Some of
these solutions, such as extensive operator training and active public education
and outreach programs, are already in place at METRORail, while others were
included in the research team's list of potential safety enhancements.
METRORail
Safety Analysis and Suggestions for Safety Enhancement
METRORail is almost
totally in semi-exclusive right-of-way with very limited lateral clearance and
some very tight constraints. Safety provisions of the design were found to be
generally adequate. Some minor adjustments to the traffic control devices and
operational practices are needed to fine tune the system and its operation to
work as intended. This includes such aspects as traffic control system
adjustments for current operating speeds and adjustment of signing. The
assessment also found that several opportunities exist to further enhance
METRORail traffic safety. These generally fall in the categories of modified
signing, minor changes in signal and LRV operation, and increased use of
pavement markings. There are additional possible enhancements that require
engineering and operational analyses to ensure that the improvements will be
truly effective and free from unintentional side effects that might create new
issues not currently existing.
Full Report PDF
