Transportation Strategy

A general approach to solving a transportation problem. Examples of transportation strategies for roadways include: "do nothing" or "no-build," add a travel lane, convert a travel lane to an HOV lane, reconstruct or widen a roadway, or implement Transportation Demand Management and Transportation Systems Management

Transportation System Management (TSM)

Actions or construction that control or improve the movement of cars and trucks on the highway system and buses on the transit system. TSM also includes the coordination of the available transportation systems for more efficient operation.

Transportation Systems Management (TSM)

Some TSM concepts represent over 80 years of experience and practice by transportation engineers and planners. A typical TSM activity is a low-cost, short-term, high-impact transportation-related improvement. A TSM action is not the construction of a new freeway, but it may be the use of a freeway shoulder as an added traffic lane during peak traffic flow conditions. TSM examples include using traffic signals at freeway on-ramps to meter traffic, improving existing signal timings, and using changeable message signs (ahead traffic condition information), lane control signs, and changeable speed signs. TSM involves making implementable improvements, or additions, to existing transportation facilities.

U

Unified Transportation Program (UTP)

A ten year planning document that guides and controls project development for TxDOT in a feasible and economical manner. The UTP is updated annually and requires approval by Texas Transportation Commission. Annual updating allows the UTP to be customized as the Intermodal Surface Transportation Efficiency Act (ISTEA) programs become better defined, and the annual updating also enables the UTP to serve as an integral part of the planning process required by ISTEA.

V

Vehicle Mile of Travel (VMT)

A unit to measure vehicle travel made by a private vehicle, such as an automobile, van, pickup truck, or motorcycle. Each mile traveled is counted as one vehicle mile regardless of the number of persons in the vehicle.

Vehicles Per Day (VPD)

This is a measure of traffic volume and is used as the unit for Average Annual Daily Traffic.

Vehicles Per Hour (VPH)

A ratio used in defining the hourly volume.

Volume-to-Capacity ratio (V/C)

The ratio of flow rate to capacity. The V/C may be the actual or projected rate of flow on a designated lane group during a peak 15-minute interval divided by the capacity of the lane group. The V/C ratio is a measure of capacity sufficiency, that is, whether or not the physical geometry provides sufficient capacity for the subject movement. Low V/C ratios depict relatively free flow conditions. High V/C ratios depict more congested conditions. Actual V/C ratios are calculated from vehicle count data (defining volume) and the geometrics of a roadway (determining capacity). V/C ratios are used to broadly define problem areas on a freeway and to make preliminary operational decisions concerning the freeway (e.g., ramp metering rates). In some cases, the V/C ratio is used to define

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