How Many Vehicles Do You Need to Store in a Drive Through Lane?

Since my days reviewing site plans in Maple Grove a decade ago, I’ve had a nagging question – how much storage should be provided in a drive through lane?  There was an article published in the ITE Journal in 1995, but that is out of date.  Mark Stuecheli prepared a study about banks and coffee shops in 2009 that was presented at the ITE Annual Meeting.  But nothing comprehensive like ITE’s Parking Generation report.

So we’ve gone ahead and laid the ground work by preparing the 1st Edition of the Drive-Through Queue Generation report. We collected video with our COUNTcams at drive throughs for two days at a minimum of six locations for five different land uses (meaning each land use has at least 12 maximum queue data points).  We also incorporated Mark Stuecheli’s data (thanks Mark).  We watched 1220 hours of total video (which we did on fast forward in about 120 hours with our PC-TAS software).  Then we put the above report together – from start to finish in three weeks (and yes we’re cracking open the beer this afternoon to celebrate).

So what did we find?  Here are our recommendations based on the 85th percentile maximum queue lengths.

Recommended Drive Through Vehcile Storage (total vehicles, independent of # of lanes)

  • Banks – 8 vehicles (160 feet)
  • Car Washes – 7 vehicles (140 feet)
  • Coffee Shops – 13 vehicles (260 feet)
  • Fast Food Restaurants – 12 vehicles (240 feet)
  • Pharmacies – 5 vehicles (100 feet)

Click the link to download a copy of the Drive-Through Queue Generation Report.

Are you interested in more trip generation data? 

If you are interested in more trip generation data, we offer free, open source trip generation data at TripGeneration.org. At TripGeneration.org you can download more than 4,080+ hours of professionally collected data on 14 popular land uses.

We are always looking to collaborate to collect trip generation data. If you’d like to partner with us to collect trip generation data in your area, we have a limited pool of COUNTcam video collection products that we’re lending for free to collect data around the country. Leave your contact information in the comments section or you are interested in the lending program or contact our Sales Sales Team at CountingCars.com.

Mike Spack

  • Haven’t read the reports but just some food for thought. I am slowly getting older so my youthful insight is becoming less and less.
    I go to the bank maybe once a year and handle both my personnel and business expenditures on my smartphone or over the phone.
    Today there are banks like ING who dont even have a physical location or USAA who serve the military.
    One question from the data you provided, it looks like 20 feet per vehicle, how well does this correspond to the video data? Thanks.

  • Bruce Newman says:

    Many fast-food and coffee drive-throughs use three-stage operations. Customers order at a talking sign, pay at a first window, and pick-up at a second window. (During off-peak times, payment is at the second window.) While this does start the queue at the payment window, closer to the street, it also reduces processing time per vehicle, which tends to reduce the maximum queue from the pick-up window.

  • mike spack says:

    Chris – We weren’t able to precisely measure the length each car took, but they appeared very cramped together when in line so we used the 20 foot length of a typical parking stall to estimate the length. But we also provided the queue length in number of vehicles so folks could tweak that length if they wanted to.
    Bruce – I’d love to see data on the three stage drive throughs. We have a few in our area, but they almost always seem to operate at the two stage method.

  • Scot says:

    Interesting, thanks for sharing. I’ve done queuing studies at drive-in banks and come up with lower numbers in DFW and Houston areas. I’d agree with the others, but like trip gen so much depends on the success/business of the user. As I say about internal cature and two-way stop-control analysis, we need a lot more grad students doing research on these things :-). I’d love to see analysis against bank location density, customer count, demographics of each area, weather, etc.
    Queue lengths we use 20′ per vehicle for tighter packed queues like drive-thrus and school queues, but 25′ for more random queuing from crashes, etc.
    Three-stage food drive-thrus vary, sometimes the bottleneck is at the payment, but it is usually at the pick-up window. We count spaces from the pick-up window. Most of the new fast-food restaurants around here are going to a two-lane setup. They realize that a congested site hurts their throughput in the peak times.

  • Alan says:

    FYI In Canada the Tim Horton’s coffee shop / fast food restaurant chain has become so popular that they need vehicle storage for up to 20 vehicles at there drive through. At older local Tim Hortons’ waiting vehicles regularly spill out onto the street – I guess their marketing department considers this a success. Tim Horton’s themselves now requires storage for at least 18 vehicles. I don’t know what they put in their coffee but people can’t seem to get enough of it.
    Thanks for your blog you have some useful stuff on here.

  • I did a little study of 4 drive thru coffee kiosk’s in the northern California City of Redding a few years ago. I used the ADT on the arterial serving the business as the independent variable and found a reasonable relationship (~0.44 queued veh/1,000 ADT). We also found that vehicles really bunch up and 20′ per vehicle was achieved.

  • We have performed several queuing analyses here in Miami, FL. We focus on the service rate data in the field rather than the actual queue at any given land use. Given the service rate and the approach traffic volume (sometimes determined using ITE trip gen), we use either an M/M/1 or M/M/s queuing model to determine the probablity of a queue to be less than or greater than a given storage length or # of cars. These models are used by Electrical, Industrial and Mechanical engineers and thier use in Traffic Engineering is well supported.

  • Jim says:

    From a land-use perspective, 260 lane-feet is enough area to house a small business. It’s not my job, but I have to wonder which is the higher and better use.

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