travel demand model
The travel demand model is a computer-based tool used to determine the future volumes and capacities of roadways throughout the region. In simplified terms, it is the closest thing we have to a crystal ball for projecting how many vehicles will use our roads in the future.
How Does the Model Work?
The TDM uses future land use data to identify areas where future residential, commercial, and industrial growth will occur. Based on this growth, the model then makes assumptions as to how much more traffic will be generated on our roadways.
Knowing which roadways are likely to be congested in the year 2040, we can model different projects to determine their impact on the roadway system. This allows us to proactively design and build projects that will relieve future capacity issues. This then allows our limited financial resources to be utilized for projects that have long-term benefits.
What are Model Scenarios?
The model allows for multiple future scenarios to be used to compare how projects address needs. For the Connect 2040 model, two different future scenarios were developed. One is based on the future land use and growth identified in the Cities' Comprehensive Plans. The other focuses on opposite assumptions and growth patterns. Our future growth won't be black or white, but rather lie somewhere within the gray area. The image to the right provides a graphic description of scenario planning.
Is the Model the Only Tool the MPO uses?
The model is only one of the tools used to determine a roadways capacity or a project's long-term viability. There are roadways shown as having capacity issues that will not be expanded to increase capacity (downtown streets, civic streets, roadways with higher pedestrian traffic), because they aren't intended to move traffic through quickly. The model also is not able to understand the impact of intersections on travel times or congestion. so while the model may show a road is "At" or "Over Capacity", if the delay is caused by the intersection (or node), adding adding additional lanes or increasing capacity will not solve the issue.