The Transportation and Land Use Coalition is using a traffic generation model (URBEMIS) to provide a scientific way to calculate the amount of traffic generated from a proposed development.  URBEMIS was developed by the California Air Resources Board with modifications by Nelson Nygaard to take transportation mitigations into account.  This methodology is improving upon the Institute of Transportation Engineers' Trip Generation Methodology that are currently the baseline. 

Presently, cities use standard techniques to estimate the number of trips generated by a proposed development or plan based on only two factors: land use type and acreage of site. 

URBEMIS considers a full suite of additional factors including:

• Residential Density
• Mix of Uses
• Proximity to and Frequency of Transit Services
• Bicycle and Pedestrian Accessibility
• Availability of of Affordable and Senior Housing
• Parking Supply and
  
• Transportation Demand Management
  

The two main goals TALC hopes to achieve using URBEMIS:

1. The model can show how a well planned Transit Oriented Development could result in significantly less driving and air pollution and greater financial savings, compared to the same size development on open space far from transit and services. 
   
2. While alternative plans are being considered, the model can be used to predict how changes in the plan could contribute to community health.  For example the model could predict how much of a reduction in driving could be achieved by an increase in affordable housing, providing free transit or car sharing, or including childcare or other amenities. 
   

Since low-income residents, seniors and people with good access to services also own fewer vehicles, community groups can use this model to advocate for less surface parking and more parks or other amenities.

TALC has used the URBEMIS model in South Hayward to compare two potential developments: compact housing near the BART station, or the same number of homes built in the Hayward hills. View a summary of TALC's traffic generation modeling in South Hayward.