Traffic Mobility Access
Definition of Transportation Vehicle travel. Person and goods movement. Ability to obtain goods, services and activities.
Unit of measure Vehicle-miles and vehicle-trips Person-miles, person-trips and ton-miles. Trips.
Modes considered Automobile and truck. Automobile, truck and public transit. All modes, including mobility substitutes such as telecommuting.
Common performance indicators Vehicle traffic volumes and speeds, roadway Level of Service, costs per vehicle-mile, parking convenience. Person-trip volumes and speeds, road and transit Level of Service, cost per person-trip, travel convenience. Multi-modal Level of Service, land use accessibility, generalized cost to reach activities.
Assumptions concerning what benefits consumers. Maximum vehicle mileage and speed, convenient parking, low vehicle costs. Maximum personal travel and goods movement. Maximum transport options, convenience, land use accessibility, cost efficiency.
Consideration of land use. Favors low-density, urban fringe development patterns. Favors some land use clustering, to accommodate transit. Favors land use clustering, mix and connectivity.
Favored transportation improvement strategies Increased road and parking capacity, speed and safety. Increased transport system capacity, speeds and safety. Various strategies to increase transport and land use system capacity, efficiency and safety.
Implications for TDM Considers vehicle travel reductions undesirable, except where congestion is extreme. Supports TDM strategies that improve personal and freight mobility. Supports TDM whenever it is cost effective.
Comparing Transport Measurements
This table compares the three major approaches to measuring transportation. "TDM" or Transportation Demand Management (also known as Mobility Management) refers to various strategies to encourage more efficient transportation.