Safety of Unseparated Express-Toll Lane

The intent of this research is to develop an analytical framework to understand and quantify the impact on safety of adding an Express-Toll lane without barrier separation. It is expected that development of such a framework will inform decisions on whether or not to construct buffer separated express toll lanes based on the understanding of their effect on safety. Phase-I of this effort is intended to be Colorado focused and will include examination of the safety effects of buffer separated express lanes on US-36 (Denver to Boulder), I-25 (120th to U36) and I-70 Mountain Express Lanes. Based on findings from these 3 corridors, a working hypothesis will be formulated about the relationship between flow parameters and safety. Building on this hypothesis, a draft procedure for evaluating potential safety effect of BSETLs on safety will be developed.

Division 01 -	General Requirements, Vehicular Access and Parking, Traffic Control, Temporary Barriers and Enclosures.
Division 32 -	Exterior Improvements, Flexible Paving, Asphalt Paving, Rigid Paving, Concrete Paving, Paving Specialties, Pavement Markings.
Division 33 -	Utilities, Storm Drainage Utilities, Storm Drainage Structures.