GreenTRIP Connect

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The dashboard that GreenTRIP Connect uses to display projections. Source: GreenTRIP Connect


GreenTRIP Connect is a free online tool that allows users to quickly estimate the average daily driving and average daily greenhouse gas emissions impacts from a proposed development. Users can then see how these estimates could be affected by strategies like unbundling parking and provided free memberships to transit, carshare, or bikeshare. In the San Francisco Bay Area, Connect can also be used to model parking demand and the space and cost savings of parking reductions. The tool is a project of transportation advocacy organization TransForm.

How it Works

To start assessing a project in Connect, a user

  1. first selects a parcel on a map.
  2. Then, using an easy graphical interface, the user enters data about the development such as number, size, and price of the units and number of parking spaces.

The tool will present estimates of driving and greenhouse gas emissions per unit and for the building as a whole. Once a projet baseline has been established, the user can select which of the four GreenTRIP Strategies to model:

  • unbundled parking
  • transit passes
  • carshare memberships
  • bikeshare memberships

Users can add data about affordable units, which impacts the VMT created by a development[1]. Connect will then model the reductions in driving and emissions resulting from these changes.

GreenTRIP Parking Database

In the San Francisco Bay Area, Connect can be used to model parking demand in the same way as driving and emissions. A user can input the price and type (surface/structure/underground) of parking to see the price and space savings associated with potential reductions in parking. This functionality is powered by the GreenTRIP Parking Database, a collection of parking information from multi-family developments around the Bay. While the sample size is relatively small (80 developments), the database is nonetheless helpful in demonstrating parking utilization at various sorts of sites. This tool is useful for planners trying to determine how much parking a development needs. TransForm is currently working on extending parking prediction to Los Angeles.


Connect bases its model on three factors: vehicle miles of travel (VMT), GreenTRIP Strategy VMT reduction, and parking prediction.

  • VMT - Using a Center for Neighborhood Technology (CNT) white paper, Connect models the VMT impact of a proposed project using four variables: income, location efficiency, household makeup, and regional context.)[1]
  • GreenTRIP Strategies - The initial VMT model is then fine-tuned based on research into four methods for reducing VMT: unbundled parking, transit passes, and carshare and bikeshare memberships[2].
  • Parking prediction - In the Bay Area, Connect can model parking effects using data from the GreenTRIP parking database and a parking model developed by CNT and TransForm[3].


GreenTRIP Connect is primarily aimed at residential developers, but planners and other government officials can use it in a variety of ways. It is easy to select parcels to get a quick snapshot of a proposed development before conducting a more thorough investigation. Because Connect is a free, simple tool, it is easy to incorporate it into the development review process by either recommending or requiring that developers do a GreenTRIP analysis on any proposed project. On a long-term level, data from Connect can be used to modify zoning codes or specific plans.

Connect is also a useful tool for community engagement. It gives members of the public a look into the development process, and because reports are generated so quickly the tool can be used in live presentations to demonstrate the effects of parking regulations, affordability mandates, or other measures.

A rendering of a GreenTRIP certified project in San Francisco. Source: TransForm

GreenTRIP Certification

GreenTRIP offers a certification program in the Bay Area. During the GreenTRIP Certification process, developers are assisted by GreenTRIP staff in modeling strategies to reduce vehicle trips, parking demand, and greenhouse gas emission. GreenTRIP will also speak on behalf of a project at public meetings, helping explain a project to a crowd that might be skeptical of both the developers and city officials[4].

Cities can use this process to guide development. For instance, the city of Emeryville has formally incorporated GreenTRIP Certification into their code. Developers of multi-unit residential projects are required submit a transportation demand management plan to show that they will create per-resident VMT lower than the city average; GreenTRIP Certification fulfills this requirement. GreenTRIP Certification has not expanded outside of the Bay, but the standard Connect reports can be generated for projects statewide.

GreenTRIP Connect