Automatic Open (Free Exit) Loop Formula
Add value to gate systems with a well thought out Automatic Open or Free Exit Loop.
By Brian Dickson

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The simple things make a big impression on customers. As installers we want to make a gate that works, but we often overlook the small features, the simple things that really make our gate installations stand out. We all know that if a customer really likes your installation they will recommend your work to a friend or neighbor and a referral is one of our best sales tools to increase business. A good exercise is to put yourself in the owners shoes and see how your system would perform under their standards.

A common overlooked feature on a gate system with loops is the automatic open. When a vehicle drives over this loop the gate will automatically open for them adding the convenience of a hands free exit. The automatic open loop is commonly known as a “Free exit loop” because no buttons are needed to be pushed to exit. The concept behind a free exit loop is the gate user already passed security entering the property, why should they pass security to go out. To get the most use of the automatic open loop, it should be installed up the driveway inside the property so that as someone is exiting by the time they reach the gate it will be completely open for them. The formula below will calculate the distance (in feet) the automatic open loop should be placed while maintaining a desired MPH.

Automatic Open / Free Exit Loop Formula

X = Time for the gate to open in seconds.
Y = Desired MPH to reach gate.
Z = Distance in feet the automatic open loop should be placed (length of lead-in)
Alternatively, if you wanted to find out how fast (MPH) a vehicle can go so that by the time they reach the gate will be completely open for them for formula would be:

Several examples of this formula would be as follows:

If a gate takes 9 seconds to open and the customer wants to drive at 5MPH: 9 x 5 x 1.46 = 65.7ft. The same gate but the customer wants to drive at 12 MPH would read: 9 x 12 x 1.46 = 167.6ft. Same customer has a very long driveway and wants to drive 19 MPH would read: 9 x 19 x 1.46 = 249.7ft. Most loop manufactures will have available a 60 and 100ft lead-in as a standard stock item. Custom lead-in lengths of 250ft are common, but are available up to 1000ft.

It is important to keep in mind that if you install an exit loop over 100' away from the gate, it is recommended that you install a second exit loop closer to the gate. The second exit loop will open the gate if the car took too long coming down the driveway, or if they stopped along the way. Not having the second exit loop could cause the customer needless frustration.

If you are not offering an automatic exit loop currently you could be missing out on your opportunity to “up sell” your installation and make additional profit. The gate operator has all the interface to perform the exit loop function, all you need to do is install a loop and detector module and the customer will  get more enjoyment from system potentially saving them time on their morning commute.

To learn more tips and tricks from the loop experts visit the BD Loops website at: Make sure to check out our educational editorials and tests and results in our special help and instructions section. While you are visiting our site find out how BD Loops superiorly design preformed direct burial and saw-cut loops can save you time on your next installation.

Brian Dickson is the General Manager of BD Loops, an assembler of preformed direct burial and saw-cut inductance loops for the gate, door, and parking industry. With over 10 years in business the quality of our loops is unheard of. BD Loops products are available through 250+ distributors nationally. The company has several letters of recommendation testifying their professionalism and design, and is a member of the following associations: AFA, IDA, CODA, NOMMA, IMSA, and IPI. Call BD Loops at 714.890.1604 or email at