Signs and Sign Policies

Purpose

To establish criteria for the installation of Deaf and Blind Child Warning signs (W15-10).

Information

The Manual does not establish any criteria for the installation of these warning signs. Therefore, the Washtenaw County Road Commission is establishing its own criteria for the installation of these signs.

Procedure

1. A resident living on a street or road under the jurisdiction of the Washtenaw County Road Commission, who wishes to have a Deaf or Blind Child warning sign installed must submit a written request to the Washtenaw County Road Commission. The following criteria apply:

   1. The hearing and/or visually-impaired child for whom the sign(s) are to be installed must be under eighteen years of age.

   2. Written verification of the child’s hearing problem and/or documentation stating the child is legally blind must be received from a school official or a licensed physician.

2. If the above criterion is met, a sign will be installed at the direction of the Washtenaw County Road Commission. The following guidelines will be followed:

   1. The Deaf and Blind Child warning signs shall be placed according to the procedures established in the Michigan Manual of Uniform Traffic Control Devices.

   2. In the case where the child is confirmed to having both a hearing and visual impairment a “Deaf Child” sign will be chosen for installation.

   3. The sign placement will be reviewed at least every two years to insure that the above criterion is still being met.

Purpose:

To establish guidelines to be followed when considering installation and placement of Deer Crossing signs (W11-3)

Information

The Michigan Manual of Uniform Traffic Control devices lists Deer Crossing signs. However, it does not provide criteria for the installation and removal of these signs. Therefore, Washtenaw County Road Commission is defining criteria to be used in the installation and removal of Deer Crossing signs.

Procedure

A deer-car accident history should be researched for the stretch of road in question. Installation of deer Crossing signs is warranted if five deer car related accidents have occurred in a twelve month period. Placement of the signs should be reviewed every third year. Any necessary adjustments in the placement or removal of the sign should be made according to the following guidelines:

• A deer-car accident study should be conducted for the stretch of road encompassing the deer crossing area and one mile to either side of the area.
• The placement of signs shall be adjusted to reflect any change in the concentration of deer-car accidents in the study area.
• When the accident study shows that no deer-car related accidents have occurred in the study area in a minimum of twelve month period, the sign may be removed at the discretion of Washtenaw County Road Commission.

This policy shall be superseded by any and all changes to the Michigan Manual of Uniform Traffic Control Devices which affect the criteria and/or placement of deer crossing signs.

The Washtenaw County Road Commission allows Neighborhood Watch signs to be placed within the right-of-way on local and subdivision roads but not on primary roads. The Road Commission works with the Washtenaw County Sheriff's Department's Neighborhood Watch Coordinator to stake proper sign locations within the county road right-of-way. It is then the responsibility of the Neighborhood Watch Association to install and maintain the Neighborhood Watch signs.

The Washtenaw County Road Commission places road name signs at the intersections of all county roads. These road name signs have yellow lettering on a blue background. The Road Commission receives frequent requests to replace or repair road name signs. When the Road Commission is notified of a missing road name sign, the signs are added to a list. If you see a missing road name please e-mail us so it can be added.

One of the most common requests received by the Washtenaw County Road Commission is for a stop sign. Stop signs are installed at an intersection only after a traffic engineering study of the existing conditions indicates that their installation is appropriate. The Road Commission follows the guidelines and warrants for installing signs set forth in the Michigan Manual of Uniform Traffic Control Devices (MMUTCD). These warrants examine the traffic volumes, crash history, traffic flow and sight distance at the location to determine if a stop sign should be used.

Each year, the Road Commission receives numerous requests for stop signs in order to reduce speeding. However, the purpose of a stop sign is to assign right-of-way at an intersection, not control speed. Research shows that stop signs installed for the wrong purposes often create more problems than they solve. While unwarranted stop signs may decrease speeds in the immediate vicinity of the sign, they actually increase speeds between the signs. Unwarranted stop signs have a high non-compliance rate which leads to a loss of respect for all traffic control devices. Proper installation of stop signs will maximize the safety and efficiency of county roads and help ensure that citizens maintain a healthy respect for the community's traffic control systems.

When a request for a passing or no passing zone is received, the Road Commission reviews that section of roadway according to the criteria outlined in the Michigan Manual of Uniform Traffic Control Devices. These criteria evaluate the available sight distance along the primary roadway and the speed limit of the roadway at vertical and horizontal curves. If adequate sight distance is not available, a no passing zone will be established.

Each year, the Road Commission receives requests to modify passing zones due to concerns from drivers being passed turning off of or onto a road in the middle of a passing zone. Unfortunately the presence of driveways or crossroads is not a factor in this analysis because traffic traveling on the primary road has the right of way to any traffic waiting to enter its flow of traffic. Keep in mind, the practice of changing pavement markings from passing zones to no passing zones in areas that meet or exceed the sight distance criteria is not a sound engineering solution to a driver whose hazardous passing maneuver ignores turning vehicles or speed limits.

General Speed Law

Under the Michigan Vehicle Code, the General Speed Law states “a person driving a vehicle on a highway shall drive at a careful and prudent speed not greater than nor less than is reasonable and proper“. The maximum speed limit on all highways is 55 mph. These speeds may not always be posted, but motorists are required to know them.

85th Percentile Speed

Speed limits between 25 and 55 mph are established on the basis of traffic engineering surveys. A traffic engineering survey analyzes the road conditions, crash history and prevailing speeds along the road. The speed limit is then set at the speed at or below which 85th percent of the drivers drive, otherwise known as the 85th percentile speed. Studies have shown that posting the speed limit at the 85th percentile speed results in more uniform traffic flow and fewer accidents. Drivers tend to be less impatient, pass less often and tailgate less, thereby reducing crashes. In addition, posting an appropriate speed limit simplifies law enforcement since blatant speeders are easily identified and law enforcement officers are not trying to enforce unrealistic and arbitrary speed limits. Under Michigan law, absolute speed limits on county roads are determined by unanimous agreement between the county road commission, the township board and the State Police.

Lower Speed Limits

The Washtenaw County Road Commission receives many requests to post a lower speed in order to slow down traffic on a road. Many studies have demonstrated that drivers tend to operate their vehicles at speeds that are reasonable and proper, regardless of the posted speed limit. Since it is the driving environment that mainly influences speed, posting signs at higher or lower speeds does not significantly change the 85th percentile speed. In addition, if an artificially low speed limit is posted, some drivers will obey the lower speed limit while many others will simply ignore it. This difference in speed disrupts traffic flow and can lead to an increase in crashes. Finally, when traffic is traveling at different speeds, the number of gaps in traffic to allow safe crossing is reduced and pedestrians and other drivers have a more difficult time in judging the speed of approaching vehicles.