Green Parking Carbon Calculator Information

Statistics for vehicle throughput and transaction/idle times are based on the following:

Eastern Virginia Medical School (EVMS) installation experience (audited by Kimley-Horn)
TransCore’s system at Eastern Virginia Medical School produced significant, measured improvement over their prox system in real world conditions. A peak time volume of 50 vehicles per minute (throughout the facility) was measured between 6-9 am and 3-6 pm. This produced an average entry/exit time of 4 seconds, a vast improvement over the 14 second average measured with the previously installed system. This more than 70% reduction in idle times contributed to a major reduction in the carbon footprint. This is a measured result of the more than 3x improvement with the RFID-based AVI system.

Carbon Calculator assumptions

Annual idle time (in hours) is calculated based on data entered: 1) number of vehicles using the system; 2) seconds of idle time for the current system. The TransCore AVI results assume a 4 second idle time as measured in the abovementioned EVMS study. Assumptions used in the basic calculation are 5 days per week operation and 2 daily transactions (in and out). The results are then uplifted to reflect 52 weeks per year to produce the annual idle time, pounds of carbon produced, and equivalent miles driven.

Advanced calculator assumptions

If multiple trips per day for a percentage of vehicles is selected, the assumption is a total of two (2) in and out trips per day. If weekend operation is selected, only one trip per day is calculated.

Emission Facts and Sources

Carbon dioxide production is based on statistics from indicating that every hour of idle time produces 20 pounds of carbon dioxide.

According to, every two minutes of car idling consumes the same amount of gas required to drive approximately one mile. Green Facts information (e.g. 1,000 lbs of carbon equivalencies) was gathered from the


Environmental Protection Agency

Numerous sources of funding for green building are available at the national, state and local levels for homeowners, industry, government organizations and nonprofits. We are providing the links on this page to help you find a variety of funding sources including grants, tax-credits, loans, or others.

EPA Green Building Funding Tool

Association for the Advancement of Sustainability in Higher Education

AASHE, the Association for the Advancement of Sustainability in Higher Education, is a member organization of colleges and universities in the U.S. and Canada working to create a sustainable future. Visit AASHE’s resource center for information to support campus sustainability work.

AASHE Website

U.S. Department of Energy is the official U.S. government source for fuel economy information and provides current, Regional and National, gas prices at

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