Doing the Alternative Commuting Transportation Survey

How to conduct your commuting survey

SSc4: Alternative Commuting Transportation, focuses on documenting your building occupants’ use of alternative transportation modes for commuting to and from the project building. Option 3 allows you to comply with the credit requirements by conducting a survey of your regular building occupants’ commuting behavior over a five-day period. In practice, the majority of project teams who attempt this credit do so with the commuter survey.

It is important to make sure that your survey adheres to SCAQMD Rule 2202 procedures, a set of guidelines that helps you to properly structure your survey and ensure that the results capture an accurate assessment of occupant commuting behavior.

The following strategy will review best practices for developing, distributing, and conducting your commuting survey. You may also refer to the sample survey language in the SSc4 Documentation Toolkit to review a completed example.

Developing the survey

General survey format

• The survey must be set up to gather data either:
  • once each day for five consecutive days, or 
  • at the conclusion of five consecutive workdays. 
• Avoid asking occupants about their commuting habits for “a typical week.” The credit explicitly requires that you survey occupants for a specific 5-day period.
• The survey may either be developed on paper or through use of online tools; if the survey is on paper, an alternative approach is to survey commuters in person as they enter the project building in the morning. 
• If you choose to do in-person interviews, make sure your questions are short and direct so participants can respond with quick, easy answers.
• If you are also attempting EQc2.1: Occupant Comfort—Occupant Survey, consider combining this survey with the occupant comfort survey in order to optimize your overall response rates.
• Unlike the occupant comfort survey, the commuting survey responses do not need to be anonymous. In fact, you may want to collect contact information in order to match up drivers and riders who are interested in carpooling.

Important questions to ask 

• The survey should ask respondents to describe how they commuted to and from work for each day of the 5-day workweek. A sample survey is available in the Documentation Toolkit of SSc4: Alternative Commuting Transportation.
• Make sure to ask whether the respondents arrive and depart the project building using the same mode of transportation.
• If a respondent uses two different transportation modes, ask that they indicate the mode used for the majority of the trip. For example, if they took a train for ten miles and walked one mile from the train station to the office, indicate that they used Public Transit.
• Make sure to ask carpoolers and vanpoolers how many other people share their commute – you will need this information in order to finish the compliance calculations properly. For any carpoolers that do not indicate how many people they carpooled with, you must use most conservative assumption of two people per vehicle.
• The survey should include questions that identify the year, make, and model of a respondent’s car, so that you can verify whether the car is a conventional vehicle, alternative-fuel vehicle, or low-emitting, fuel-efficient vehicle with a qualifying ACEEE Green Book score.

Only include regular building occupants

• The survey should be configured for regular building occupants only. This includes full-time employees and excludes building visitors or retail customers.
• Each survey respondent must identify the transportation mode used to travel to the project building from 6:00–10:00 a.m. on each day of the survey period.
• An alternative timeframe may be used if your building has unique occupancy patterns, but it must be a 4-hour window between 4:00–11:00 a.m., and the same window must be used for all five days of the survey period.

Distributing and conducting the survey

• The survey must be conducted either once each day for five consecutive days or at the conclusion of five consecutive workdays. The survey period must be during a typical workweek that does not include any holidays and falls during a time of year that accurately reflects seasonal variation in commuting behavior. Performing one survey at the end of five days is the most common strategy used to document this credit.
• The survey should not be announced ahead of time to avoid skewing the responses or prompting unrepresentative behavior during the survey period.
• Only regular building occupants can be included in the survey. The following assumptions should be used in determining commuting behavior:
  • Regular occupants who are absent on one or more days of the survey period because they telecommute or work a flex schedule must be listed as making zero trips for the day.
  • Employees who are absent from the office on business trips for one or more days of the survey period must be listed as making zero trips for the day.
  • Respondents who walk, bicycle, use public transit, or use a fuel-efficient vehicle are counted as making zero trips for the day.
  • Respondents who carpool or ride-share for more than 50% of their commuting trip distance are counted according to the number of other commuters in the vehicle. For example, if two people carpool to work together, each is counted as making 50% of a trip; three carpoolers are counted as making 33.3% of a trip each, and so on.
  • Respondents who report vacation or sick leave days should be noted but may not be included in the calculated results.
• There are two different compliant approaches to distribute the survey to building occupants.  Decide which of the following approaches you would like to use before the performance period
• Approach 1: Distribute the survey to the entire population of regular building occupants.
  • LEED does not require a minimum response rate for this survey. However, unless you receive responses from at least 60% of all building occupants, you must rely on a discounted extrapolation scheme, per a key LEED addendum.
• Approach 2: Distribute the survey to a randomly selected, statistically representative sample of the building population. The representative subset completes the survey and the results are then extrapolated to the entire building population.
  • If you choose this approach, you must document the statistical validity of the sample population and explain the methodology used to determine the sample size.
  • Use this formula to determine the required minimum sample size; the constant “752” should be used by all projects to ensure statistical validity: Required Random Sample Size = (# of Regular Occupants x 752)/ (# of Regular Occupants + 752)
  • It is very important that you document the exact number of surveys that are distributed to your random sample. This value will be required to calculate your compliance level once you have the survey results.
• For buildings with many visitors or transient occupants, such as museums or hotels, you are only required to survey the regular building occupants. Visitors can be excluded from the survey if they represent more than 80% of the total anticipated commuting trips to the project building on an average day. However, if your project building falls into this category, you must document the infrastructure or programs intended to facilitate visitors’ use of alternative transportation.