Manual Notice: 2006-2
From: Mark A. Marek, P.E
Manual: Roadway Design Manual
Effective Date: October 01, 2006
Purpose
This revision is intended to update the Roadway Design Manual and, specifically, add a new Chapter 8, Mobility Corridor (5R) Design Criteria.
Contents
Chapter 8, Mobility Corridor (5 R) Design Criteria, is being added to the Roadway Design Manual to provide geometric design criteria for design speeds of 85 mph to 100 mph. Since higher allowable operating speeds are possible in the future, higher design speeds should be considered when planning new facilities or reconstructing existing applicable corridors. While a higher operating speed may not be safe or appropriate in all instances (such as densely developed urban areas), higher design speeds should be considered whenever prudent.
With respect to facilities that one day could be part of the Trans-Texas Corridor (TTC), particularly new location routes, it is strongly recommended that these facilities be initially designed to accommodate a 100 mph design speed. Even though the facility may initially be posted for an 85 mph speed, the higher design criteria will allow the greatest flexibility, both in the roadway portion as well as for other transportation modes within the right of way, in terms of maximizing the future use of the corridor.
This does not mean that all projects should be over-designed. If, through the project development process it is determined that substantial, adverse and unavoidable social, economic and environmental impacts will occur, then different design criteria may be appropriate. Contact the Environmental Affairs Division and the Right of Way Division as questions arise about environmental and right of way impacts while planning for higher design speeds.
Instructions
This revision will be distributed online only.
This manual, and all revisions, applies to all highway and street project development, whether developed by the department or with consultant staff. This manual, and all revisions, will be effective for all projects beginning with the April 2007 letting. Project development using this manual and its revisions prior to that date is at the option of the district.
Contact
For general comments and suggestions for future revisions of this manual, contact the Design Division, Roadway Design Section.
Archives
Past manual notices are available in a pdf archive.