VTRANS Prioritized Needs 2019 - 2023

Through VTrans, Virginia’s statewide transportation plan, the Commonwealth Transportation Board (CTB) adopted a vision, goals, and objectives. The goals and objectives support the VTrans vision and shape how we measure progress and how we identify transportation needs and solutions. Measures enable us to quantify progress toward achieving the goals and objectives.

VTrans Needs: VTrans identifies mid-term needs to advance the goals and objectives established by the Commonwealth Transportation Board (CTB) over the next 10 years. Extensive stakeholder consultation is conducted before any modifications are made to the policy to identify and prioritize needs.

VTrans Prioritized Needs: Once the VTrans mid-term needs are identified, they are then prioritized to allow greater fo-cus on locations that have more pressing needs or locations with several overlapping needs.

Travel Time Index (TTI): Travel Time Index (TTI) is the ratio of the travel time during the peak period to the time re-quired to make the same trip at reference (aka typical) speeds. For example, a TTI of 1 indi-cates average conditions or reference speed while a TTI of 1.3 indicates a travel time that is 30% longer than free-flow conditions. A higher number indicates more congestion.

Planning Time Index (PTI): Planning Time Index (PTI) is the ratio of the 95th percentile travel time to the free-flow travel time and indicates the planned travel duration that is required for an on-time arrival for 95% of trips on a given segment. For example, a PTI of 1.6 at a given time means that a trip that takes 15 minutes in average conditions or reference speed should be planned to take 24 minutes (15 x 1.6 = 24) to ensure that 95% of trips will arrive on time.

Level of Travel Time Reliability (LOTTR): Level of Travel Time Reliability (LOTTR) measures the dependability of travel time from day to day. It is calculated as the number of hours where the ratio of longer (80th percentile) travel times to “normal” (50th percentile) travel time exceeds 50%. A higher number indi-cates less reliable travel.