APPENDIX 2. Classification of the distance out from road center line that different types of road projects are projected to impact.

The values presented here are the distance from road center line that different types of road construction projects will impact for California State highways. The distances were developed by Caltrans biologists and planners. A project footprint as described in the text would use this distance to buffer each side of the road, for the length of the project. This footprint can then be used to sample biological resource layers such as land cover maps, species locality maps, etc.

Project Type Footprint Width (Meters)
New alignment 152.4
Reconstruct interchange and access ramps 61.0
Construct expressway 61.0
Construct new bridge 45.7
Widen roadway 30.5
Remove rail trestle 30.5
Realign curve 30.5
Grade separation improvements 30.5
Construct expressway existing alignment 30.5
Slow vehicles lane 15.2
Passing lanes 15.2
Construct lane 15.2
High occupancy lanes 12.2
Stabilize slope 9.1
Rehabilitate roadway 9.1
Construct noise barrier 9.1
Construct left turn lane 9.1
Construct retaining wall 6.1
Install median barrier 6.1
Roadside rest areas 3.0
Install warning devices 1.5
Install message signs/traffic operation systems 1.5
Install ramp metering 1.5