Data Analysis Updates Travel Demand Model
TMACOG is a regional storehouse of data that is combined and analyzed to forecast how transportation activities can affect air quality, congestion, road repair costs, level of service, and much more. Collected data is used as a tool to aid in the transportation planning process, reducing guess work. One powerful tool that combines socioeconomic data with road infrastructure data is the Travel Demand Model (TDM).
To maintain the TDM, TMACOG actively collects information from throughout the region. TMACOG planners use a variety of sources of information but also get on the phone and call jurisdictions in Lucas and Wood counties, the three southern townships of Monroe County, and a small portion of western Ottawa and Sandusky counties. They ask for news about any changes to interstates, ramps, arterial roads, and major collector roads. Changes could include adding turn lanes, adding additional lanes or widening a road, changing a speed limit, converting streets from one-way to two-way, or closing a street. This information is then entered into the model, creating an accurate description of area roads. Functions running in the background of the model forecast what the changes will mean. The model is charged with simulating existing traffic patterns and projecting future travel demand. For example, projections from the model may indicate that a particular project, such as the addition of a left turn lane at a busy intersection, will reduce travel delays and improve the level of service in the area.
Currently, TMACOG staff is bringing the model up to base year 2010 which will correspond with Census data. Socioeconomic information from the Census data links to the TDM to better predict travel patterns throughout our region. As soon as the base year model is complete, staff will create future year model networks containing projects related to the 2035 Plan and the 2012-2015 Transportation Improvement Program (TIP). When these future networks are coded, the model will be run to determine how future projects will impact air quality in the region. The model can also show the difference between “build” and “non-build” options. For example, we can compare how traffic will move if we widen a stretch of I-475, as opposed to if we don’t widen, but add new entrance and exit ramps.
Sample of a Travel Demand Model entry screen. This area includes the
I-475/Airport Highway intersection showing McCord Road where a railroad grade separation is planned. The blue lines are the highway network. The gray lines are centroid connectors in the model. Those lines represent local roads and include socioeconomic data about residents and employment in that area.