Despite these annual expenditures, there is a general void in terms of a consolidated effort that attempts to quantify proven benefits of pavement markings. Over the years, many research projects have focused on specific elements of pavement markings. This paper discusses and references early landmark studies, but an emphasis has been placed on some of the more recent studies because significant strides have been made to identify pavement marking benefits. Many of these recent studies have been the beneficiary of advanced technologies that allow for innovative research methodologies. When combined with lessons learned from previous research, the most recent research offers new insights into the benefits of pavement markings that were previously undetectable. This paper was developed to bring together many of the recent and ongoing research efforts to demonstrate a renewed perspective regarding the benefits of pavement markings and, where information is available, describe the benefits of various aspects of pavement markings. This paper presents areas where conclusive findings are available, and describes areas where findings are available but show inconsistent and sometimes conflicting results.

Ideally, this paper would focus exclusively on crash studies and cost-effectiveness studies. As described earlier, however, there is not an exhaustive amount of safety-related information on pavement markings. In lieu of safety data, other measures of effectiveness have been used to assess the benefits of pavement markings. This paper describes four common measures of pavement marking performance: safety studies, subjective evaluations, vehicle operational studies, and visibility-related studies. Uncommon or unique measures of performance are also described.