Guide Sign Replacement
"Overhead highway signs must be highly visible and legible so that drivers can detect, read and interpret the information contained on the signs in time to respond appropriately."
Evaluation of New Reflective Material for Highway Signage
Bullough, et al
Rensselaer Polytechnic Institute
Research Report No. C-05-08
Guide signs are important tools that help drivers navigate safely—often on complex, high-speed and high-volume roadways. Confused drivers can lose focus on the driving task and may make erratic maneuvers, such as slowing or stopping in the roadway, backing down ramps, or making abrupt turns. It is important that guide signs are highly visible and legible, both day and night.
There are several factors negatively affecting the nighttime performance of guide signs. First, visually/optically-aimable (or VOA) headlights that have a sharp, horizontal cut-off direct less light toward overhead signs. Second, there is a wide range of vehicle sizes on today’s roads, and signs perform differently for drivers of large vehicles. These drivers experience a greater "observation angle" (the angle created between a vehicle’s headlights and the driver’s eyes) and typically receive less retroreflected light from signs. Lastly, the U.S. population is aging and the number of older drivers is on the rise. By 2020, the number of persons 65 and older will exceed 50 million. Older drivers have decreased visual acuity and benefit from signs made with high performance reflective sheeting. 3M™ Diamond Grade™ DG3 Reflective Sheeting is designed to provide optimal performance for all types of signs—including signs in disadvantaged locations—and help meet the visual needs of all drivers.
State departments of transportation across the U.S. are looking for ways to improve guide sign visibility and save taxpayer dollars. Many are finding one solution that helps achieve both goals by upgrading to guide signs made with high performance, “full cube” reflective sheeting from 3M, while at the same time cutting maintenance and energy costs by turning off guide sign lighting.
Minimum performance levels still exist for guide and street name signs; however, these types of signs are excluded from the assessment/management method June 2014 compliance date. The final rule states that "types of signs other than regulatory or warning are to be added to an agency’s management or assessment method as resources allow."
Under MAP-21, guide sign replacement programs may be eligible under the National Highway Performance Program (NHPP) which is intended to improve the condition and performance of the National Highway System (NHS). This program gives states greater flexibility to address the most vital needs for highways and bridges on the NHS, while holding states accountable for improving outcomes and using tax dollars efficiently. NHPP funding is $43.7 billion total for the two years covered by MAP-21.
NHPP provisions include:
- Construction, reconstruction, resurfacing, restoration, rehabilitation, preservation or operational improvement of segments of the National Highway System (including bridges and tunnels).
- Inspection and evaluation of highway infrastructure assets on the National Highway System, including signs and sign structures.
- Highway safety improvements for segments of the National Highway System.
- Development and implementation of a State asset management plan for the National Highway System including data collection, maintenance, and integration and the cost associated with obtaining, updating and licensing software and equipment required for risk-based asset management and performance-based management.
Funding may also be available through the Surface Transportation Program (STP) which is designed to give state and local governments broad flexibility to invest in highway, transit, and pedestrian/bicycle projects that fit their particular needs and priorities. Half of each state’s STP funds must be divided among areas of the state based on population, while the remaining half of the funds may be used in any area of the state. STP is funded at $20.1 billion total for the two years covered by MAP-21.
STP provisions include:
- Construction, reconstruction, resurfacing, restoration, rehabilitation, preservation or operational improvement for highways;
- Inspection and evaluation of highway assets, including signs;
- Highway safety infrastructure improvements and programs, including those on local and rural roads;
- Development and implementation of a State asset management plan for the NHS.
Another funding avenue is the Highway Safety Improvement Plan (HSIP) which is a key mechanism for funding safety improvement projects HSIP funds nearly double in 2013 and 2014, from $1.3 billion in 2012 to $2.39 billion in 2013 and $2.41 billion in 2014.
HSIP-eligible projects include "installation, replacement, and other improvement of highway signage and pavement markings, or a project to maintain minimum levels of retroreflectivity;" a project to maintain minimum levels of retroreflectivity "without regard to whether the project is included in an applicable State strategic highway safety plan"; systemic safety improvements (i.e., "an improvement that is widely implemented based on high-risk roadway features that are correlated with particular crash types, rather than crash frequency"); and collection, analysis, and improvement of safety data. "Minimum levels of retroreflectivity" projects were added to the list of safety improvements, including traffic signs and pavement marking upgrades, that can be funded at up to 100 percent federal share.