Traffic Speed Reduction in Marbrey Landing
The Board of Directors have received written comments from several homeowners
who have raised concerns about vehicles traveling in excess of the posted 25
mile per hour speed limit. Enforcement of the speed limit by the local
police department would effectively curtail a majority of these occurrences.
In 2004, the District One Uniform Patrol of the Durham Police Department was
invited to our neighborhood by the Marbrey Landing Homeowners Association Board
of Directors to observe the speeds motorist were traveling through our
neighborhood. During the first week of March they parked a radar- equipped
surveillance device called the "speed wagon" on Armitage Drive. The speed
wagon is equipped with a large yellow numerical display showing the speed a
motorist is traveling in real-time. The speed wagon is battery powered and
it's equipped with a solar panel to provide a charge to the battery package.
The trailer operates silently and it completely self contained with everything
necessary to operate 24 hours per day/ 7 days per week. It appears to have
provided the needed incentive for motorist to slow down when traveling through
of neighborhood. Our thanks to Captain
Jim Bjurstrom, District 1 Commander, Durham
Police Department ; 919 560-4281 ext. 242; he's credited for working with the
MLHOA Board, the speed wagon was his idea. Captain Bjurstrom indicated "we
like to set up the speed trailer at first to let neighborhoods know that we are
monitoring the area." The Uniform Patrol will be back in our neighborhood
ready to handout citations to motorists speeding through our neighborhood.
Please drive safely
through Marbrey Landing
In 2004, we discovered there were only two speed limit signs installed
throughout our neighborhood and both of them were located on Armitage Drive.
We contacted
Captain Jim Bjurstrom for
assistance and advice. He put us in touch with
Terry Thompson of the Department
of Transportation (DOT); 919-560-4366. Mrs. Thompson arranged to conduct
an assessment of our neighborhood speed limit signs during the first week of
March. Five additional speed limit signs were installed, two on Marbrey
Lane and three more on Thistlerock Lane. We also discussed the idea of
having other street signs installed in our neighborhood such as those displaying
"Speed Strictly Enforced by Radar" and "Children At Play" with Mrs. Thompson.
She's quoted with the following reply;
"Please be advised that the standard
speed limit signage in a neighborhood is a black on white regulatory
speed limit sign. The Police Department will enforce the speed
stated on the regulatory sign. The 'Speed Checked by Radar'
is used on highways. If the Police Department is going to set up
regular radar speed detection vehicles in the neighborhood, we will
discuss the use of such a sign with the Police Department."
"The 'Children Playing' sign is not a
lawful traffic control sign in Durham. Children are not allowed to
play in the street, and that especially goes for children playing
basketball in the street. Basketball goals are allowed only on
private property. The Police Department can cite the parents of
children that are obstructing traffic by playing basketball in the
street. However, children are allowed to ride bikes on a street
when they abide by the traffic laws."
"I think the speed wagon is a good
idea as a reminder to all who travel on the streets of your
neighborhood. My experience is [that] what really slows people down is
their conscientious behavior, which signs are used as a reminder of...
and a police car in their rear view mirror."
During the time the DOT conducted their survey, they discovered multiple
violations of a North Carolina State Statute that basically prohibits children
from playing [basketball] in the street. They advised the Board that this
is a Class 2 Misdemeanor and homeowners who do not relocate their portable
basketball goals no less than 10 feet from the street curb onto their own
private property, are not in compliance with the statute. They indicated
they will permanently remove the basketball goals, by force if necessary if
those homeowners fail to comply with a written warning from the Homeowners
Association and or the Department of Transportation.
SPEED HUMPS
The implementation of speed humps (a.k.a. "calming devices") in our
neighborhood is considered by some homeowners to be the favored solution to
reducing excessive traffic speed. People across the United States are opposing
the installation of deflection devices on city streets that damage vehicles,
injure vehicle passengers, increase pollution and gas consumption and delay
emergency response. In the opinion of many people in communities
throughout the United States, these devices are considered as a last resort when
all other options have been studied and exhausted.
Installing street humps is not a small project nor does it have a small
impact. Nothing should be implemented, or even considered, unless there
is strong urging from residents along the affected roadway. Even then, there are
a number of things that should be evaluated and implemented before installation.
1. Traffic engineering studies of the area need to be done to determine if
the path in question is a good candidate for speed humps utilizing the criteria
mentioned earlier. These studies include safe sight distance, pedestrian
activities, vehicle classification, traffic count, speed studies. Current land
use, school routes, "as built" plans, other control devices, and stop sign
compliance should also be examined.
2. If the traffic engineering studies show that there is a prevailing
problem, the next step should be to enforce existing laws and ordinances
regarding speed limits, revising them if necessary.
3. The third strategy is to educate residents on the causes of the speed
problem and the potential solutions to it. They should be well informed on the
advantages and disadvantages of each possible solution. This can be done in a
number of ways including town meetings, flyers, posters, and door to door
education.
4. Installation of traffic control devices, including regulatory, warning,
and guide signs, in conformance with the Manual on Uniform Traffic Control
Devices, is the next step.
5. Consider legal liability. Review the current laws and regulations
regarding speed humps. Courts have held the installing agency liable for damage
and personal injuries resulting from speed humps.
6. If none of the above strategies alleviates the speed problem, then speed
humps should be considered. The plan, however, should not be implemented until
other alternatives have been explored, all groups affected are informed and/or
consulted concerning the matter, and traffic engineering studies have been
conducted and conclude that there is a need for speed humps.
Advantages |
Disadvantages |
- They are relatively easy for bicycles to
cross if designed appropriately.
- They are effective in slowing travel speeds.
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- Speed Humps are expensive. They cost
the City of Durham $1,200 each to install according to the
Department of Transportation. In 2003 approximately 80
speed humps were installed by the DOT, costing an estimated
minimum of $96,000.
- They cause a "rough ride" for all drivers,
and can cause severe pain for people with certain skeletal
disabilities.
- They force large vehicles, such as emergency
vehicles and those with rigid suspensions, to travel at slower
speeds.
- They may increase noise and air pollution.
- They have questionable aesthetics.
- They frequently cause damage to vehicles,
even at normal speed levels, but it is legally very difficult to
make a claim against a local authority as a result. This problem
particularly affects older, heavier vehicles or those with low
ground clearance.
- Speed humps create additional road
maintenance costs because the road surface before and after a
hump tends to develop potholes after a couple of years. This
results in much heavier maintenance costs than normal. In
addition to fully resurface the road it is often necessary to
remove and replace the speed humps, which also adds to the cost.
- In addition, they can affect drainage of
rainwater
- Speed humps also restrict the ability of the
city to clear snow and ice off the streets you can't plow over a
speed hump.
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Speed Hump Design and Installation Issues |
Potential Impacts |
- Speed Humps are typically 12 to 14 feet in
length; other lengths (10, 22, and 30 feet) reported in practice
in U.S.
- Shapes include parabolic, circular, and
sinusoidal.
- Heights range between 3 and 4 inches with
trend toward 3 - 3 ½ inches maximum.
- Difficult to construct precisely.
- Often have signage (advance warning sign
before first hump in series and warning sign or object marker at
hump).
- Typically have pavement marking (zigzag,
shark's tooth, chevron, zebra).
- Taper edge near curb to allow gap for
drainage
- Some have speed advisories.
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- May have no effect on non-emergency access.
- Speeds determined by height and spacing;
speeds between humps have been observed to be reduced between 20
and 25 percent on average.
- Based on a limited sample of sites, typical
crossing speeds (85th percentile) of 19 mph have been measured
for 3½ inch high, 12 foot humps and of 21 mph for 3 inch high,
14 foot humps; speeds have been observed to rise to 27 mph
within 200 feet downstream.
- Speeds typically increase approximately 0.5
mph midway between humps for each 100 feet of separation.
- Studies indicate that traffic volumes have
been reduced on average by 18 percent depending on alternative
routes available
studies indicate that collisions have been reduced on
average by 13 percent on treated streets (not adjusted for
traffic diversion).
- Most communities limit height to 3-3½ inches,
partly because of harsh ride over 4-inch high humps.
- Possible increase in traffic noise from
braking and acceleration of vehicles, particularly buses and
trucks.
- Concern over jarring of emergency rescue
vehicles.
- Approximate delay of between 3 and 5 seconds
per hump for fire trucks and up to 10 seconds for ambulance with
patient.
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Several studies have been published on the subject that are
worth reading. We recommend interested readers conduct their own search
for more information.
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