6.1.6 Travel Lane Width and Number of Lanes

Travel lane widths may vary from 10 to 12-ft depending on the context classification of the facility and anticipated target speed.
12-ft travel lanes are recommended on all roadways that are part of the Texas Highway Freight Network (THFN).
The number of lanes required to accommodate the anticipated traffic in the design year is determined by the level of service evaluation as discussed in the
HCM
.
The typical range of lanes for collectors is one to two travel lanes in each direction.
6.1.6.1 Rural
Rural collectors should be designed to 12-ft due to the higher operating speeds usually associated with these types of facilities.
11-ft lanes may be used on two lane collectors that:
  • Have an operating speed of 45 MPH or less and a future ADT less than 2,000 VPD;
  • Have an operating speed of 60 MPH or higher and a future ADT less than 400 VPD; or
  • Have an operating speed of 70 MPH or less and a future ADT less than 1,500.
10-ft lanes may be used on two lane collectors that:
  • Have operating speeds of 55 MPH or less and future ADT’s less than 400 VPD.
6.1.6.2 Rural Town
Rural town collectors should provide 12-ft lanes due to the agricultural vehicles and trucks that will drive on these types of facilities. 11-ft lanes may be used in restrictive ROW conditions.
Lane widths may be reduced to 10-ft in highly constrained areas where both the following conditions are present:
  • Truck and bus volumes are low (less than 5%); and
  • The anticipated operating speed is less than or equal to 35 mph.
Engineering judgement must be exercised when determining if a 10-ft lane width is acceptable.
Use of 10-ft travel lanes must be approved by the District and approval documented in the project file.
6.1.6.3 Suburban, Urban, Urban Core
Suburban, urban, and urban core collectors will commonly use 11-ft lanes on facilities with lower operating speeds as a traffic calming measure (i.e., 45 mph or less). If the anticipated target speed is 50 mph or greater and or truck volumes are significant (>10%), 12-ft lanes should be used.
Lane widths may be reduced to 10-ft in highly constrained areas where the conditions described in 6.1.6.2 are met.