February 13


Estimating Trip Generation and Distribution for a Wedding Venue

By Mike Spack

February 13, 2018

10th Edition Trip Generation Manual, trip gen special occassion, Trip Generation, tripgeneration.org, wedding venue

By Mike Spack, PE, PTOE

Kent Harbert from the Colorado DOT reached out to me wondering if we have trip generation data for wedding venues.  We don’t, but we’ve estimated trip generation for a couple of wedding venues and I emailed our rough process to Kent.  Kent ran with it and put together the draft guideline below for use in Colorado.

Why am I sharing this with my readers? I want to share this with you as it’s a good process to think through for estimating trip generation at special events.  I would however, like to get your thoughts on calculating trip generation data for special events.

  1. What Do You Think? Kent and I would like to hear from you if you have thoughts on the guideline. Please add your thoughts to the comment section.
  2. Wedding Venue Data. If you have trip generation data for wedding venues, please email data to me at mspack@spackconsulting.com and we’ll add it to our free TripGeneration.org dataset. I’d like to share your data with Kent and the rest of the world.

From Kent Harbert, Colorado DOT:

The ITE Trip Generation Guide does not include a land use category for wedding venues. It is, therefore, desirable to establish a standard methodology to project the trip generation rates and the trip distribution assumptions. The following is proposed:

Trip Generation

A wedding is a single event at a pre-established time. All of the wedding party and wedding guests will be in attendance at the ceremony. Therefore, the trip generation rate will be based on the capacity of the area within the venue to be used for the ceremony.

Typically, a wedding party will rent a venue with a capacity near the size of their wedding. Estimate that 75% of the venue capacity will be the typical size used for trip generation.

Estimate that the wedding party and vendors represent 10% of those attending the wedding and that they arrive more than one hour before the ceremony. The remaining 90% will arrive during the one-hour period before the ceremony.

Many of the wedding guests travel together as couples, families or groups of friends. Assume there will be 2 to 2.5 guests per vehicle.

Using the above factors gives a range of 0.27 to 0.33 for the trip generation factor as a function of the venue capacity. Use an average rate of 0.30 with 100% entering.

If the venue does not include a reception area use the same 0.30 rate for the exiting trips. If the venue has a reception area the exiting traffic will be dispersed over a few hours. Use a rate of 0.12 (0.30 x 40%) for the peak hour of exiting vehicles.

Trip Distribution

Trip distribution for a wedding venue is not like other land uses where the traffic in one direction plus the traffic in the opposite direction totals to 100% of the design hour volume. For a wedding venue the majority of the traffic can be to and from one direction for one wedding and to and from the other direction for a different wedding. The two distributions need to be analyzed separately, not averaged.

Free Trip Generation Data at TripGeneration.org

At Spack Consulting, we collect local data on many, if not most, of our traffic studies. And we make that data available to you for free. This living document now includes over 10,500 hours of data and allows you to see the full 24-hour data collected. Go to TripGeneration.org to download the raw data we’ve collected.

Interested in helping us collect trip generation data? We have a limited supply of COUNTcam 2 traffic video recorders that we lend to companies to collect traffic data, and make available on TripGeneration.org. If you would like to use a camera to collect your next turning movement count and participate in our trip generation data collection, please contact us at sales@countingcars.com.

Mike Spack Bio

  • Based on an email from a reader, here’s a clarification on “For a wedding venue the majority of the traffic can be to and from one direction for one wedding and to and from the other direction for a different wedding. ” This type of scenario is for the ceremony at a different site (likely a church) and then the reception at this venue. If the main access is on a north/south road, a trip distribution scenario and analysis should be run once for a church that is north and once for a church that is south. These two different scenarios can be quite different and need different mitigation. Mike

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    Mike Spack

    My mission is to help traffic engineers, transportation planners, and other transportation professionals improve our world.

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