Nashville MPO: Enagaging Active Transportation at the Regional Level
January 31, 2011 1 Comment
The Nashville Metropolitan Planning Organization (MPO) is doing amazing work regarding active transportation. They have been recognized nationally for their work in this regard. They provide a great example of engaging active transportation in the development of a Regional Transportation Plan (RTP).
Leslie Meehan, a Senior Transportation Planner, and also nationally recognized leader on Active Transportation, was kind enough to walk me and a few of my colleagues through their work. Thanks Leslie!
The Bicycle/Pedestrian Non-Motorized Trip Generator Model was part of the Nashville Area MPO Regional Bicycle and Pedestrian Study. The model is a parcel-based model that makes predictions about the number of bicycle and pedestrian trips from a parcel to a destination based on the proximity of the parcel to a destination. For example, if a household is a half-mile from a library, the model allocates a number of trips that may be taken from the parcel to the destination. The model takes into account 8 trip types — walk or bike to school, walk or bike to recreation, walk or bike to work, walk or bike to shop, walk or bike to errands from work, walk to transit, walk from transit, and walk from parking (downtown parking lots). The inputs for the model include national household data, the MPO Community Viz land use allocation model, data from InfoUSA on business types, a regional transit survey and others.
The output is displayed in GIS and the trips are allocated to a quarter-mile grid to make the display of the information more easily seen at a regional level. We have a brief mention of the model in the Study Technical Memorandum #2 – Needs Assessment (pp.21-23) and in a separate but brief Non-Motorized Model Document. The model output map is also attached. This is a composite map for all trips, where green means a prediction of 5 or fewer trips per day up to red which means 200 or more trips per day by bicycle and pedestrian mode. We have the ability to break down the map by mode type, but we have not done this yet in GIS.
Bicycle and pedestrian models have limitations because these models are hard to calibrate due to lack of bike/ped count data. These models must make some assumptions, so the results should be taken with a grain of salt. However, this model is unique in that it is the only model we are aware of that looks at trips from a parcel level versus a Traffic Analysis Zone level (which typically correlates with census block groups). We felt that doing a parcel-based model provided a more accurate representation of bicycle and pedestrian trips since many of these types of trips are short in nature.
Our hope is to link this bike/ped trip model with our land-use allocation model so that we can predict the effect of future land use changes on bicycle and pedestrian trips. This type of future mode share allocation has never been done for bicycle and pedestrian trips, although it is quite common for motorized modes. If we are able to do this, we could see what the changes a new residential development, school, park, etc. would have on the demand for bicycle and pedestrian trips.
The following link is to the document which describes the process used and outcomes of our first regional bicycle and pedestrian trips counts in five counties. As mentioned, we plan on conducting the counts every-other year.
Regional Transportation Plan
As mentioned, our Regional Transportation Plan incorporates many elements of health, environment, and safety into the scoring criteria for all projects considered for the plan. About 60% of the criteria are based on active transportation, safety and health and have resulted in nearly 70% of the transportation projects chosen having active transportation infrastructure. We also set aside 15% of our STP funds for active transportation, resulting in about 2.5 million over the next couple of years to spend on bicycle and pedestrian infrastructure and education, outside of the work already begin done as part of other projects – e.g. a road widening project that includes a sidewalk and bike lane. The documents that will be probably be of most interest to your are the Goals and Objectives, Evaluation Factors and Scoring Criteria where we specifically address health and active transportation. The Draft Urban STP Investment Strategy is where we address the 15% set aside for active transportation.
We primarily addressed equity by prioritizing our active transportation infrastructure projects (sidewalks, bikeways and greenways) by census tracks containing high numbers of impoverished, elderly and minority populations. These census categories were assigned points so that a project in an area with a high concentration of one of two groups got 2 points, if two groups overlapped the project got four points, and if all three groups overlapped the project got six points. The entire project criteria can be found in our Technical Memorandum Project Evaluation Methodology.
Since these populations also roughly translate into those with the highest amount of health disparities, highest amount of obesity and related diseases such as heart disease, and highest amount of households without a car, we felt that we were providing not only a transportation facility, but also an opportunity for physical activity (shown to positively impact the occurrence of obesity and related diseases).