August 16


Announcing New Parking Generation Data

By Mike Spack

August 16, 2016

Free-source, local trip generation, parking, Parking Generation, trip gen, Trip Generation

We have done a lot of talking lately about trip generation and how we have been collecting our own local data, as well as getting data from other people around the country. Having all of this trip generation data has been a great benefit to us at Spack Consulting. We’ve been able to use the data in many of our traffic studies.

Since we have all of this great data, we were wondering what else we could do with it. Though there are probably many different uses for all of this data, the first thing we thought of was to get parking generation information.

Parking Generation Data. 

The amount of parking planned in a new development can make or break whether the development is a success or if it even gets built. Having information on how much parking needs to be provided on site can be of great importance to developers, traffic engineers, government staff and anyone else involved in parking management.

The Institute of Transportation Engineers has a Parking Generation Manual similar to their Trip Generation Manual. The information in this manual is very valuable and we have used it many times in the past. However, as we have discussed many times over before, having recent, locally collected data is always better.

The parking generation data we have is based on our trip generation data and is calculated by taking the entering data less the exiting data for each 15-minute interval. Parking lot counts were not conducted at the beginning of each trip generation count, so the number of cars in the lot at any one time is not guaranteed to be accurate. The way useful data was found was by finding the maximum parking demand which was the difference between the highest and lowest parking numbers for each day.  This maximum parking demand was then divided by the number of units to give a unit rate.


The parking demands do not factor in vehicles parking in locations other than the designated parking lot for the location and vehicles using a location at a drive-thru lane or fuel pump are included in the parking data. Also, vehicles that did not leave the parking lot over the course of the day are not factored in. Because of these reasons, some caution should be exercised when using this data.

As our trip generation database grows, so will our parking generation database.  We are excited for this additional use of the data and to be able to continually improve on it.  Let us know if you have any other good ideas for how to use trip generation data or if you have any data you’d like to add to our database.

Download your Free Parking Generation Data with 25 land uses at

Get Parking Generation Data

If you’d like to partner with us to collect trip generation in your area, we have a limited pool of COUNTcams video collection products that we’re lending for free to collect trip generation and parking generation data around the country. Leave your contact information in the comments section if you’d be interested in the lending program or contact Sales at

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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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