U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
| REPORT |
| This report is an archived publication and may contain dated technical, contact, and link information |
|
 |
| Publication Number: FHWA-HRT-17-075 Date: March 2018 |
Publication Number: FHWA-HRT-17-075 Date: March 2018 |
Florida and South Carolina provided data, including the locations and dates of the installation of profiled thermoplastic pavement markings. Reference sites were also identified in each State that were similar to the treated sites in terms of traffic volumes and roadway geometry but had other than profiled thermoplastic lane markings. These States also provided roadway geometry, traffic volumes, crash data, and information on other construction activities for both installation and reference sites. This section summarizes the data assembled for the analysis.
This section describes the installation data, reference sites, roadway data, traffic data, crash data, and treatment cost and service life data for Florida sites used in this evaluation.
The Florida Department of Transportation (FDOT) provided a list of installations of profiled thermoplastic markings. FDOT applied the treatment mostly on rural two-lane undivided roads with some use on rural multilane divided roadways. The profiled markings were used for the edge lines. The treatment site data provided include the following installations:
Data from the year of installation were excluded from analysis. No other construction activities were reported at these locations.
Reference sites were chosen by selecting roadways in the same counties as the treated locations with the same functional class and similar levels of traffic volume and geometrics.
FDOT provided roadway inventory data that included the following variables:
FDOT provided traffic data from 2005 to 2013 in the form of annual average daily traffic (AADT).
FDOT provided crash data from 2005 to 2013, including many variables related to the location, time, and characteristics of each crash.
A range of treatment cost and service life data were provided by FDOT for various contracts. Examination of these data suggested that they were reasonably consistent with the more specific information available for South Carolina, so it was decided to apply the South Carolina Department of Transportation (SCDOT) costs for the economic analysis based on the combined results of the two States.
The information provided by FDOT suggested that a service life of 3 years could be assumed.
This section describes the installation data, reference sites, roadway data, traffic data, crash data, and treatment cost and service life data for South Carolina sites used in this evaluation.
SCDOT provided a list of installations of profiled thermoplastic markings. Most installations were on rural two-lane undivided roads but with some installations on rural multilane divided roadways. The markings were only applied on the edge lines, and application took place in 2011 and 2012. Additional installations in the northern districts of the State had subsequently been removed through snowplowing operations, and these were not included in this study. Data for the installation year were excluded from the analysis. The total length of installations used for this study was 341 mi. The installation information included the route number, mileposts, and construction period.
No other construction activities were reported at these locations.
Reference sites were chosen by selecting rural two-lane and multilane roadways with characteristics similar to the treated sites and from the same districts as the treated sites.
SCDOT provided roadway data from 2005 to 2014 that included the following variables:
SCDOT provided traffic data from 2005 to 2014 in the form of AADT.
SCDOT provided crash data for 2005 to 2014, including many variables related to the location, time, and characteristics of each crash.
SCDOT provided estimated cost information of $0.50/linear ft for profiled thermoplastic pavement markings. The application cost for edge-line applications was $5,280/mi for two‑lane roads and $10,560/mi for four-lane divided roads. The estimated service life is 5 to 7 years.
For flat-line thermoplastic pavement markings typical of the untreated reference sites, SCDOT estimated an installation cost of $0.40/linear ft, with a service life estimated at 5 years.
Table 1 defines the crash types used for both States. The project team attempted to make the crash type definitions consistent. In both States, intersection-related, snow/slush/ice, and animal crashes were excluded because these crash types were not considered correctable by the treatment under study. Note that sideswipe crashes in Florida were not analyzed because a coding change occurred during the study period; no sideswipe crashes were reported in later years at the treatment sites, and the crash coding for sideswipe crashes was not considered reliable.
Table 2 provides summary information for the data collected for the treatment sites. The information in table 2 should not be used to make simple before–after or between State comparisons of crashes per mile-year because such comparisons would not account for factors, other than the strategy, that might cause differences in safety between the before and after periods or between States. Such comparisons are properly done with the EB analysis, as presented later.
Table 3 and table 4 provide summary information for the volume and roadway data for the treatment sites, and table 5 provides summary information for the reference site data. Comparisons of crash rates between States and between treatment and reference sites should consider that the rates were only per mi and traffic volumes were not considered.
