IMPROVED SIGNAGE

Goal

Improve driver awareness of curves, oncoming intersections, hidden drives, etc. through the use of signage that is easily seen at all points throughout the day.

WHAT IS IT?

Signage is an important component for motorists and other roadway users. Signage provides information for location and direction; warning of upcoming roadway features; and instructs the motorist on proper usage of the roadway. The placement and quantity of signage on roadways is typically based on engineering specifications, studies, or best judgement related to traffic volume and roadway features, such as the curvature of roads. Signage acts as an important guide and warning for drivers in countless situations keeping them aware of their surroundings.

Sign visibility is important to allow motorists proper time to react. Retroreflectivity is an important feature of signage at night. Retroreflectivity is the optical phenomenon where the rays of light are reflected directly back to its source. This allows drivers to more easily see signage and reduces sign glare on adjacent properties. The level of retroreflectivity can determine whether a driver misses a sign and potentially causes a crash. Retroreflectivity should be evaluated to ensure that signs are clearly visible from a distance offering proper time to stop if needed. Putting signage in combination with one another has shown a decrease injury related crashes and non-injury related crashes. Partnering warning signs (turn/advisory speed signs) with others will continually bring attention and give information to the driver.

When motorists approach a curve signage may be needed to properly warn motorists of its severity. Chevron alignment along curves help to signify the sharpness of a curve. Chevrons should be installed four feet above the roadway surface and outside the curve, in line with the approaching traffic. Spacing of chevrons are determined by the curve radius and advisory speed. This tactic has seen a decrease in crashes when installed on rural highway curves. Directional arrow signs can also be used to define sharp curves. Usually they will appear on the outside of the curve per direction for the curve/turn. It is suggested that these signs could be used in combination with chevrons and/or doubled up to increase awareness.

The size of the signs themselves should also be thought about for the areas in which they will be located. The minimum size of signs is not recommended by the Manual on Uniform Traffic Control Devices (MUTCD) but allow them on low-speed roads where the reduced size is still adequate for the warning or if physical conditions prevent the installation of a larger sign. Oversized or larger signs should be used in special applications where speed, volume of traffic, or other factors result in the need for a larger sign (determined on studies or an engineer’s recommendation).

Doubling up on signage would involve installing a second identical sign on the left side of the roadway (instead of just one sign on the right). Doubling signage increases the chances of a person seeing the sign and responding appropriately, and potentially will increase visibility in case of an obstruction of the sign located on the right side of the roadway.

Potential Conflicts

Constant maintenance will be required to check on visibility. Making sure that trees or other vegetation don’t cover the sign and that they are up to their retroreflectivity standards will be important.

Cost

Low cost

Top image - signage that is clear of any foliage

Bottom image - retroreflective signage to highlight an upcoming curve