The Commission maintains and operates a regional transportation software model to perform travel analysis and forecasting. The software includes a regional map of the various roadway and transit systems and allows a user to estimate and model changes and scenarios in the system before implementing them in the real world. Traditionally, an approach known as the “four-step process” has been used for regional transportation planning analysis. As its name implies, this process has four basic phases:
1. Trip generation (the number of trips to be made)
2. Trip distribution (where those trips go);
3. Mode choice (how the trips will be divided among the available modes of travel); and
4. Trip assignment (predicting the route trips will take).
By looking at these four areas, we can answer the following sample questions:
How many trips will people make? Based on proximity to services and other destinations.
Where will jobs and people locate? Where people originated and are destined for – “attracted” to.
How will people travel? What mode of transportation will they choose and when?
What routes will people take? Which routes will people will take from start (origin) to finish (destination) assuming the quickest is the most desirable, but taking into account potential congestion, traffic signal delay and other variables.
The Model is also used to evaluate transportation projects for their ability to improve mobility and reduce emissions. Planners and policy makers use this analysis to make more informed decisions about implementing transportation improvement projects.