Located in metropolitan Atlanta, Gwinnett County, Ga.,
with a population of 615,000 has the lowest crash, injury and fatality rates in
Georgia for counties with populations greater than 200,000. This article
outlines the county's safety programs in order to assist other local
governments in North America improve their traffic safety programs.
The Gwinnett County Department of Transportation is very
proactive in meeting its mission of providing "a safe and efficient
roadway." The county has been successful at adopting many traffic safety
initiatives. They include about $1 billion in locally funded road improvements
since 1986; school and pedestrian safety; accident analysis; and residential
speed control. Other improvements include the adoption of positive offset
designs for left turn lanes, a raised median policy for arterials; a policy to
pave shoulders on rural two lane road; a traffic counting program; as well as
joint projects with the Georgia DOT, to name a select few.
Locally funded road improvements
The county has passed five funding initiatives to pay for
improving the safety of roads in Gwinnett County. The program has paid for
widening roads and paving dirt/gravel roads and bringing them up to current
design standards.
Gwinnett County was a rural county in the 1980s with a
population of only 167,000. The county was the fastest growing county in the
U.S. for many years in the late 1980s. This growth required brining the road up
to current design standards, as well as improving capacity. Other funding
categories included road safety and alignment improvements, bridges, culverts
and roadway drainage improvements, intersection improvements, rehabilitation
and resurfacing, transportation planning and funding for city transportation
projects.
The investment in traffic safety is as follows:
1986 Bond $114
million
1988 Sales Tax $113 million
1992 Sales Tax $266 million
1997 Sales Tax $334 million
2002 Sales Tax $192 million
Total Local Funding $1,019
million
The Sales Tax Program has been such a success for the
citizens of Gwinnett County that the 1997 and 2002 Sales Tax Program included
funding for new police and fire stations as well as a park system. The Gwinnett
County School Board has also passed their own sales tax program for building
new schools and improving old schools. The citizens are investing in the future
of their county.
Sales Tax Program
The county works with the school board to find projects
that will improve the safety of elementary, middle and high schools. Projects
included adding sidewalks that connect schools to nearby residential areas,
adding turn lanes at school entrances, improving or creating new access roads
for the schools and/or installing new traffic control devices near the schools.
Pedestrian safety has been a long-term goal for the
county. Sales Tax funds have installed more then 120 miles of sidewalks on
existing roads. Most new road improvements include sidewalks on at least one
side of the road. Crosswalks and pedestrian signals have been installed at all
signal locations in the county that have pedestrian activity.
The county has widened most the arterials in the area
from two lanes to four or six lane roads, most with a raised median to maximize
safety. Most of the two lane roads were just paved farm roads that were not built
to state standards. All widened roads are built to current state standards.
Because of clean air problems, the county's widening program has slowed down in
the past five years.
Intersection projects improve traffic safety by adding
left and/or right turn lanes as well as adding capacity of additional through
lanes that are built. The main criteria for intersection improvements are
listed on the county's high hazard list. Most of the top 50 intersection have
been improved.
The county also has developed a pioneering residential
speed control program including a current speed table program. These programs
solved a perceived safety problem on residential streets, Before-and-after
studies have found that the speed tables have reduced crashes. The Sales Tax
Program pays for the construction of speed tables and homeowners are assessed
an annual fee of $12 per year to permanently maintain the speed tables.
Sales Tax funds have been used to purchase the county's
document imaging system for accident records, fund a Comprehensive
Transportation Plan as well as other ad hoc planning studies. The planning
funds were used to hire Georgia Tech to research raised medians to help develop
the policy.
Because the county is not able to fund widening projects,
it was determined that they improve rural roads before growth makes widening or
realigning the roads impossible or too expensive. A preventative traffic safety
measure study looked at all two lane rural roads to find horizontal and
vertical curves that did not meet state road design standards. These projects
are prioritized based on traffic safety and volume.
Accident analysis
The county conducts an annual review of the Top 100
intersections. From this data, cost-effective improvements are recommended for
the next Sales Tax project.
The county accident record system is used to fix
operation problems reported by the police departments. All road defects on the
reports are forwarded to the county's maintenance department in order to be
repaired. The system also recovers damages to county property. Claims are sent
to the insurance companies for county property damaged. This property includes
traffic signs, traffic signal controllers, guardrail, fire hydrants and other
property.
The county worked with Georgia Tech and the Georgia
Governors Office of Highway Safety to develop an Expected Values Table for
intersections in the county. The tables are signalized or unsignalized
intersections with varying approaching traffic volumes. The tables show the
county which intersections have crash experience greater than the 90th
percentile for that type of intersection.
The county's traffic engineering staff works with the
police department in investigating fatal and serious injury traffic accidents.
The DOT supplies the police department with a monthly report of the top 50
crash intersections and the police use this for their enforcement activities.
The Police Department is working with the DOT and the
county's ITS department to provide electronic copies of their crash reports and
database to the DOT. This enables the DOT to process the crash records quicker
so the county can analyze the data quicker to identify safety problems.
The DOT handles over 10,000 citizen requests annually,
many of these are about traffic safety issues.
The accident record system is used to do before-and-after
studies on road improvements or traffic control devices installation. The most
recent study found that traffic signals installed in 1995 increased total
accidents at 19 intersections studied.
Adopting policies
The county has adopted policies to improve traffic
safety. In 1991, the Board of Commissioners adopted a policy to use raised
medians on all major road improvements and to replace two-way left turn lanes
on existing roads when possible. Retrofitting two-way left turn lanes with
raised medians reduces accidents by an average of about 40% on the two projects
in the county.
The DOT has implemented an aggressive program to retrofit
two-foot paved shoulders on rural two-lane roads, thus reducing low shoulder
accident potential. The county has installed over 100 miles of improved
shoulders.
The DOT has adopted a positive offset design for left
turn lanes. This design greatly improves sight distance for left turning
vehicles and does so cost effectively.
Teamwork with county cities
There are 14 cities in Gwinnett County and they all
depend on the county for their traffic engineering services. Additonally, the
county allows the cities to participate on the county Speed Table Program if
they agree to the Board traffic calming policy.
The county provides money to the cities every year to
they can repave their streets. A similar program is provided to help the cities
handle their drainage and stormwater problems.
The DOT provides signal timing and signal maintenance for
all signals located in the cities. The county also pays for the installation
costs for new signals in the cities.
Joint projects
Gwinnett County and the Georgia DOT have combined their
resources to address traffic safety and operation problems in the county. This
has resulted in the county designing and constructing state routes and the
Georgia DOT designing and constructing county roads. Senior staff regularly
meet to ensure that transportation issues are addressed by both state and
county DOTs in Gwinnett County. These meetings help the two groups to work
together and solve operational problems that may be traffic safety-related. A
recent example involves added dual left turn lanes to SR 124 at the Ronald
Reagan Parkway.
Maintenance operations
The Operations Division is responsible for a wide variety
of projects to maintain the roads on Gwinnett County. These projects involve
keeping the grass cut to ensure sight distance at intersections as well as
keeping the guardrails in good condition. Many of these jobs are contracted out
so that they are completed in a timely manner.
The county also maintained over 600 traffic signals, over
1,000 miles of pavement marking and over 80,000 traffic signs. The traffic
control devices are reviewed on a planned timetable to ensure they are
functioning as designed.
Sight distance certifications
The DOT requires the developer's engineer to seal his
plans such that he certifies that they have designed all intersections in the
development to county standards. This has improved the safety of all new
intersections and has ensured that the county has very little new sight
distance problems.
The county developed vehicle actuated flashing warning
signs for intersections that have inadequate intersection sight distance. Many
of these intersections are being rebuilt to current AASHTO design standards as
part of the Sales Tax Program.
Traffic counting
The Gwinnett County DOT has a traffic counting program
that includes over 1,000 traffic counting stations in the county, all counts
are which published on the county website. Each year, the county tries to count
600 stations for a 24-hour period. This solves the problem of real estate
persons and other from wasting county time giving them traffic counts. The
website allows county officials to spend their time on more productive matters,
including traffic safety analysis.
The traffic count information also is used in safety
analysis to do rate studies and to apply the accident experience of the study
intersection to the county's expected values table.
Components of crashes
Road, vehicle and driver-at least on of these components
is at fault in every crash. Traffic engineers control only one variable, that being
the road. The vehicle is engineered by the manufacturers with help from the
many regulations of the U.S. DOT. The driver s regulated by the state they live
in as driving laws vary in each state, each of which have adopted the basic
"Rules of the Road." The DOT works to improve the roads and works
with the police department to improve the driver by enforcing the driving laws
in the county.
Formula for traffic safety
Gwinnett County has the safest roads in Georgia for
counties with a population over 200,000, according to the most recent Georgia
Highway Safety Fact Book. The county is proud of their safety record but they
always feel they can do better.
The county would like to compare their safety records
with other states but because all 50 states have different crash reporting
standards, this is not possible. However, the DOT continues to work at
improving traffic safety in Gwinnett County.
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