Transportation and Mobility Subcommitte
Meeting 2: Monday, May 17 (5-7:15 pm)


Travel Demand Model Information

The following information was presented to the subcommittee by Mike Conger of TPO.

I. Summary of Travel Demand Model uses and outputs.

A.     It can allow comparisons to be made between existing and future conditions (looking out 10 to 20 years) to test impacts of different scenarios on various measures such as:

1.)    Traffic Volume –

        • Changes that result from background growth of demographic and socio-economic factors occurring locally and regionally.
        • Comparison of different “Build” scenarios of various improvements such as JWP extension or widening Chapman Highway.

2.)    Volume-to-Capacity Ratio –

        • Measure to describe congestion by comparing the traffic volume to the theoretical carrying capacity of the roadway.

3.)    Average Travel Time – 

        • Model reports link travel times for different time periods including morning peak, afternoon peak and off-peak.
        • Can look at different scales such as the amount of travel time to traverse the entire corridor from Blount County to downtown, or shorter segments such as from Stone Road to Moody Avenue. 
        • Can map out “travel time contours” to show how the amount of time it takes to get from areas in South Knoxville to key destinations such as downtown Knoxville changes in the future for the peak hour commute.

4.)    Peak Speed – 

        • Model computes the average link speeds for the most congested 15-minute time period for the day, which is used for computing a level-of-service.
        • Again, the links can be aggregated to the desired scale for corridor or segment analysis.

5.)    Percent Time Congested – 

        • Model computes the amount of time during the entire day that the roadway is operating at below “ideal” conditions in terms of delay.

B.     Transit sketch planning tool – A potential ridership can be estimated for a new bus route that is being considered.

C.     Air quality – Mobile source emissions that contribute to ozone formation can be computed.