EBOM-v4.1 LTp1: Transportation Performance Required

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Intent

To reduce pollution and land development effects from transportation.

Requirements

Conduct a transportation survey of building occupants on their commute patterns.

Regular building occupants must be surveyed. Building occupants shall provide information on their two-way commutes over one work week and consider seasonal variations and variations in work schedules. Visitors are encouraged to be surveyed, especially if the daily average is greater than the number of regular building occupants. Visitors shall provide information on their one-way travel to the building for that day in particular.

The required number of responses that must be received is outlined in Figure 1.

Conduct the survey at least once per year, using the Arc Platform, and calculate a Transportation Performance Score for the project.

Obtain a minimum Transportation Performance Score of 40. Additional points for this prerequisite are awarded for Transportation Performance Scores above 40, according to Table 1.

Table 1. LEED Points for Transportation Performance Score

Figure 1. Required Responses Rate for Survey

Equation: Response rate= 100 * (0.25 / square root (occupancy / 500))

The Transportation Performance Score

The transportation performance score rates the project’s greenhouse gas emissions measured in carbon dioxide equivalent emissions (CO₂e) resulting from transportation to and from the building against other high performing buildings worldwide.

The score is a value from 1-100 based on the project’s average carbon dioxide equivalent emissions (CO2e) per one-way trip per occupant (lbs.).

Transportation Performance Score Calculation

To calculate a transportation performance score, the following data is required. All data is collected via the transportation survey. At least one survey every 365 days must be conducted:

• Number of regular building occupants and visitors
• For Hospitality projects, number of hotel or lodging guests (these occupants may be excluded from the survey even though they are considered regular building occupants).
• Regular building occupant survey responses
  • # of routes for 2-way commutes over one week
  • Per route,
    • Commuting transportation mode(s),
    • Distance traveled (in miles or kilometers)
• Visitor occupant responses
  • Commuting transportation mode(s),
  • Distance traveled (in miles or kilometers)

An emissions value is calculated for each building occupant that completes the survey as follows:

1. A CO2e value is calculated for each route provided for the occupant, using the commuting transportation mode(s), distance traveled, the CO2e per mile values in Table 2 and Equation 1:

   Equation 1: CO2e for route (lbs.) = (CO2e lbs./mile) * distance traveled in miles

   Table 2. CO2e values for a one-way trip, for each mode of transit

   Mode	CO2e pounds/mile	Source
   Walk, bike, telecommute	0	NA
   Motorcycle	0.26	DEFRA/DECC 2014: emissionfactors.com
   Heavy rail	0.33	American Bus Association Foundation.  Updated Comparison of Energy use & CO2 Emissions From Different Transportation Modes, 2008.
   2-3 Carpool	0.39	EPA: http://www.epa.gov/cleanenergy/energy-resources/refs.html
   Light rail	0.44	American Bus Association Foundation.  Updated Comparison of Energy Use & CO2 Emissions from Different Transportation Modes, 2008.
   Alternative Fuel Vehicles	0.44	U.S. DOE National average for a 2014 Nissan Leaf: fueleconomy.gov
   Bus	0.68	American Bus Association Foundation.  Updated Comparison of Energy Use & CO2 Emissions from Different Transportation Modes, 2008.
   Car (solo)	0.93	EPA: http://www.epa.gov/cleanenergy/energy-resources/refs.html
2. For each occupant, CO2e is calculated using Equation 2:

   Equation 2: CO2e for individual occupant (lbs.) = (∑ CO2e for routes) / # routes

   For visitors, calculations include one route (as their survey includes only one way and one day)

   For regular building occupants, calculations may include more than one route (as their survey requests information regarding two way commutes over one week, and includes all seasons/yearly variations). Each route is weighed equally.

An average emissions value is calculated by taking an average of the individual emissions, using Equation 3.

Equation 3: Project CO2e per one-way trip per occupant (lbs.) = (∑ CO2e for individual occupants) / # occupants in survey

The project’s average CO2e per one-way trip per occupant (lbs.) value is then input into the transportation scoring function (see Figure 2) to produce a transportation performance score:

Figure 2: Transportation scoring function

The transportation scoring function was developed using transportation patterns reported by LEED buildings, certified under LEED O+M v2009. The data set includes buildings that earned SS credit 4 Alternative Commuting Transportation.

What does it cost?

Cost estimates for this credit

On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.

Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.

This information is also available in a full PDF download in The Cost of LEED v4 report.

Frequently asked questions

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