29-08-2017, 11:55 AM
In NCHRP Project 3-69, "Designing High-Speed Roadway Construction Work Zones," researchers at Pennsylvania State University developed guidelines for the design of geometric features, including horizontal and vertical alignment, transverse features, and barrier temporary concrete placement. The research team also developed a work zone velocity prediction model that estimates free-flowing vehicle speeds through two types of construction work zones on four-lane highways: single-lane and mid-lane latching.
The research team reviewed literature and ongoing research related to the design and safety of work areas. A study of state DOTs was also conducted. Survey responses and a review of the state DOT websites provided substantial information on current DOT work zone design policies and guidelines. The survey also identified priority issues associated with the design of construction work zones, and these priorities guided the research effort. Seventy-five percent of respondent states rated better guidance on traffic barriers and design as the "most important / critical" need. The roadside design and the barrier placement guide include a discussion of the concept of clear zone and its applicability to construction work zones, identification of hazards in the work area that may require treatment or shielding and cost-
The subject of speed is inextricably connected to the work zones. There is a broad perception that speed is one of the most important factors in traffic accidents. The work zone velocity prediction model allows designers to develop a speed profile to detect inconsistencies in construction work zone designs.
The research team reviewed literature and ongoing research related to the design and safety of work areas. A study of state DOTs was also conducted. Survey responses and a review of the state DOT websites provided substantial information on current DOT work zone design policies and guidelines. The survey also identified priority issues associated with the design of construction work zones, and these priorities guided the research effort. Seventy-five percent of respondent states rated better guidance on traffic barriers and design as the "most important / critical" need. The roadside design and the barrier placement guide include a discussion of the concept of clear zone and its applicability to construction work zones, identification of hazards in the work area that may require treatment or shielding and cost-
The subject of speed is inextricably connected to the work zones. There is a broad perception that speed is one of the most important factors in traffic accidents. The work zone velocity prediction model allows designers to develop a speed profile to detect inconsistencies in construction work zone designs.