This paper was presented at the "Low-volume highways and municipal road networks" session. These proceedings are available on CD-ROM. The main function of partially paved shoulders (PPSs) is to improve safety and reduce maintenance. As well, any tendency to edge cracking is moved from the travel lane to the partially paved shoulder, thereby extending pavement life. Safety is improved by minimizing pavement edge drop off and reducing granular maintenance. Property damage is also reduced and driver comfort increases because of a perceived increase in road width. This paper is based on a study of 180 PPSs sections, and is directed toward quantifying the safety and economic benefits. Motivation for the study came from a climate of economic restrictions and the associated need to quantify any benefits of PPS's. Survey and evaluation procedures are described in the paper, as is the innovative life-cycle cost approach. Based on the survey, the majority of people did not feel that gravel shoulders were safe and found them to be a dramatic exit from the roadway. Gravel fly up was identified to be a major concern and 80% of those surveyed had experienced broken or cracked windshields while 73% had experienced paint chips and 8% had encountered broken headlights due to gravel fly up. The results show that PPS's have definite safety benefits; moreover, granular PPS's had a significantly longer service life than earth PPS's. Performance equations and life-cycle costs which quantify these results are provided. Finally, the paper presents conclusions and recommendations toward those situations where partially paved shoulders are warranted for safety and economic reasons. (A)
Samenvatting