U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
With this method, pavement marking installations are recorded and, using historical data or research results, a schedule for replacing the markings before they fall below the MUTCD minimum levels is established. If historical data or research results are not available, pavement markings installed with the same materials on similar roadways (pavement surfaces and vehicular volumes) can be monitored to determine their service life (i.e., their in-service life before falling below the MUTCD minimum levels).
Although there are many variations to this method, the basic idea is that the installation of pavement markings is tracked so that agencies know when the markings were installed and on what roadway (so that they may track at least the key factors such as pavement marking type, pavement surface, and traffic volumes). Research has routinely shown that pavement marking type, pavement surface, and traffic volumes are important factors needed to understand the longevity of pavement marking retroreflectivity.(22,23)
To track the installation of the markings, it can be useful to use a computerized management technique, but that does not mean an expensive off-the-shelf system. A spreadsheet listing the roads, the markings on the road, the type of pavement, and the traffic volumes would be appropriate. On the other hand, fully featured GIS systems could also be developed. Either way, pavement markings of similar type can be grouped with roadways of similar surface types and traffic volumes. Then, using a specific roadway section representing other roadways sections with similar characteristics, the agency could track the retroreflectivity of the specific roadway section. The roadway section should be long enough to accommodate the selected method used to assess the retroreflectivity along that section of roadway (calibrated visual inspection, consistent parameters, or measured retroreflectivity). The selected section of roadway should include as many features and characteristics of the common grouping as feasible. For instance, it should include center lines and edge line if the common group is mostly two-lane roadways.
When this method is used, the management technique allows the agency to track and even predict (within reasonable limits), when the monitored pavement marking retroreflectivity will reach the end of its life. Before the marking reaches that point, the agency can begin planning to re-apply or replace all the markings that the monitored markings represent.
If an agency monitors pavement markings on a continuous basis, this method can help an agency determine if the degradation is occurring as expected. If the degradation is not occurring as fast as expected, then the pavement markings service life can be extended. Conversely, if the deterioration is occurring faster than expected, the agency can schedule the markings for replacement sooner. Monitoring changes in degradation can help ensure better nighttime visibility and increase the overall life cycle of an agency’s pavement markings, resulting in cost savings.
The use of service life based on monitored markings as a maintenance method is currently being employed in a variety of States. Pennsylvania and Florida use a combination of subjective inspection, test deck data, manufacturers’ information, past experience, and retroreflectivity measurements. North Dakota, Iowa, and Oregon have detailed retroreflectivity measurement programs to track pavement marking service life.
Either historical data or research results can be used with an expected service life method. Regardless of which is used, the service life period must be based on the MUTCD minimum levels (or higher). If pavement markings are to be monitored, they must be assessed at specified intervals to determine how they are performing with respect to the minimum pavement marking retroreflectivity levels. The trending retroreflectivity levels from the monitored markings can be used to trigger pavement marking replacement or reapplication.
While this method does not require as much inspection of markings in the field, it does require that agencies track when and where their pavement markings were installed. Using this method, agencies can also develop a more thorough understanding of pavement marking retroreflectivity durability and make adjustments to their policies as field data and pavement marking costs indicate.
Compared to measuring pavement marking retroreflectivity for all longitudinal markings, this method minimizes exposure of the inspector. In order to implement this method, agencies must determine how best to group similar pavement markings and other key factors such as pavement surface types and traffic volumes. In addition, agencies must determine the sampling procedures for the monitored markings (such as those outlined in ASTM D7585(11)) as well as the frequency of inspections (perhaps once per year at a minimum).
It is important to understand that this method relies on either known service life values (from historical data or research) or can be used by agencies to begin tracking their markings of similar type to develop service life values, so that this method is feasible in the future. When an agency knows the service life values for pavement markings, it should still consider monitoring some markings to validate and adjust those values. Service life values based on transversely applied test decks or warranty information may not be as reliable as service life values obtained from long line test decks.
When an agency uses this method to determine service life values based on monitored markings, an important aspect is that the markings selected to be monitored must be markings installed on roadways representative of the agency’s jurisdiction. They cannot be markings installed in the maintenance yard or another convenient area without traffic. Because pavement marking retroreflectivity is so closely tied to pavement surface types and traffic volumes, the control method as described and permitted for maintenance of traffic sign retroreflectivity is not an appropriate method for maintaining pavement marking retroreflectivity
(22)Migletz, J., J. L. Graham, D.W. Harwood, and K.M. Bauer, "Service Life of Durable Pavement Markings," Transportation Research Record: Journal of the Transportation Research Board, 1749 (2001).
(23)Sathyanarayanan, S., V. Shankar, and E. T. Donnell, "A Weibull Analysis of Pavement Marking Retroreflectivity Inspection Data," Transportation Research Record: Journal of the Transportation Research Board, publication pending.
|< Previous||Table of Contents||Next >|