# Door opener at grocery store **URL:** \ **Category:** Factual Questions\ **Created:** [July 14, 2005, 5:40pm UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539 "2005-07-14T17:40:14Z")\ **Posts on this page:** 11\ **Page:** 2
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [July 15, 2005, 9:32pm UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/21 "2005-07-15T21:32:26Z")
> [@Balthisar](#): > > The crappy aiming is an artifact of being either a quick walker or being tall. Well, that explains why I’m always smacking into the door. I’m both. ---
**Author:** ![ouryL](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ouryl/32/6067_2.png) [@ouryL](https://boards.straightdope.com/u/ouryL)\ **Post date:** [July 15, 2005, 10:25pm UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/22 "2005-07-15T22:25:27Z")
> [@pkbites](#): > > At one time all the grocery stores all had doors that would open automatically when you stepped upon a black rubber mat that lay about 4-5 feet in front of the door. They worked great. As you walked the doors swung open. there was some kind of trip switch under that black mat. > > Today every door at any store is opened by a sensor using X-band radar. When the radar gun senses movement, the door opens. What bugs the bejebbers out of me is, it seems none of those things is aimed right. Perhaps I walk faster than the average bear, but I’m always right on top of the stupid door before it opens. I always have to change my stride or I’ll end up bumping into the door! :mad: > > What exactly is the benefit of using this type of system or the black mat method? I would think the old method (which worked better) would be far, far cheaper than a device that has to generate a radar signal. Why did everyone go to this system, and why can’t they make it open the door about 3 seconds sooner? 😕 The doors here will open if you push them, even if they are automated. 😕 ---
**Author:** ![Beware\_of\_Doug](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Beware\_of\_Doug](https://boards.straightdope.com/u/Beware_of_Doug)\ **Post date:** [July 15, 2005, 10:34pm UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/23 "2005-07-15T22:34:51Z")
**DOR-MATIC.** Just recalled the name on all those black mats from my childhood. Only just now figured out the cleverness of it (dor-MAT-ic). It’s now apparently the name of a company in Singapore. ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [July 15, 2005, 10:37pm UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/24 "2005-07-15T22:37:32Z")
> [@ouryL](#): > > 😕 The doors here will open if you push them, even if they are automated. 😕 It depends upon the type of door. Those that slide to one side require a **a lot** of force to swing open (they **are** to designed to do that, however), and the ones that swing open normally require varying amounts of force depending upon who makes them, and whether or not they’re equipped with a “handicapped assist” mechanism. ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [July 16, 2005, 3:59am UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/25 "2005-07-16T03:59:37Z")
> [@Balthisar](#): > > I invariably have the same problem. Whew! For a minute there I thought I was the only one having that problem. The thing is, while walking into a grocery my mind is occupied by what the funk I’m going into there for in the first place (eggs, butter, milk, tampax, bread…WAIT A MINUTE!:smack: She tricked me again!!:eek: ) and not thinking about a door doing it’s job and WHACK!:mad: Right in the upper shoulder! ---
**Author:** ![Hilarity\_N.Suze](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hilarity_n.suze/32/6223_2.png) [@Hilarity\_N.Suze](https://boards.straightdope.com/u/Hilarity_N.Suze)\ **Post date:** [July 16, 2005, 6:59am UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/26 "2005-07-16T06:59:01Z")
I don’t understand what being tall would have to do with it–except for the fact that if you’re tall, probably your legs are longer and you’re a faster walker. I don’t see that factoring into the radar at all as it would pick up part of you–maybe not your head… OTOH I once worked at an office that had a keypad to get in and some kind of a sensor that released the lock, to get out. In the winter, when I had my black leather Stealth Coat on, I had to do a crazy little dance in front of the door to get it to open, or else go out behind some other people. It never affected anyone else that I knew of, and people laughed at me when they saw me jumping around in front of the door. And on at least one occasion my boss caught me before I could get out, and made me do more work. ---
**Author:** ![Larry\_Mudd](https://avatars.discourse-cdn.com/v4/letter/l/f14d63/32.png) [@Larry\_Mudd](https://boards.straightdope.com/u/Larry_Mudd)\ **Post date:** [July 16, 2005, 8:10am UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/27 "2005-07-16T08:10:09Z")
> [@Shoeless](#): > > Well, that explains why I’m always smacking into the door. I’m both. I’ve got _just_ the shoes for ya. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [July 16, 2005, 3:45pm UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/28 "2005-07-16T15:45:36Z")
My wife’s real short. She has the opposite complaint. She literally goes under the radar and the doors won’t open at all. By the time she’s close enough to be in range, she’s under the beam. This is less true now than back in the 80s when the radar/sonar door openers first came out. Her habit was to wave one arm over her head as she approached to door. Looked dumb as all get out, but it worked. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [July 16, 2005, 5:16pm UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/29 "2005-07-16T17:16:32Z")
2 reasons a store would like a radar opener that works too slowly: –If you can slow down a fast walker, he’ll see more stuff he needs to buy. –The radar triggers radar detectors in cars for a mile around, making the neighborhood traffic slower and safer. The old rubber mats would freeze up in the winter, and not work at all. ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [July 16, 2005, 5:57pm UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/30 "2005-07-16T17:57:02Z")
> [@AskNott](#): > > 2 reasons a store would like a radar opener that works too slowly: > > –If you can slow down a fast walker, he’ll see more stuff he needs to buy. > –The radar triggers radar detectors in cars for a mile around, making the neighborhood traffic slower and safer. But theres almost nothing to see in the entry way of a store. Maybe bubblegum machines. And the fuzzbuster crowd tends to ignore X-band warnings as very, very few police departments use the X band guns anymore. ---
**Author:** ![Mister\_Rik](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mister_rik/32/491_2.png) [@Mister\_Rik](https://boards.straightdope.com/u/Mister_Rik)\ **Post date:** [July 16, 2005, 11:33pm UTC](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539/31 "2005-07-16T23:33:16Z")
> [@Hilarity N. Suze](#): > > I don’t understand what being tall would have to do with it–except for the fact that if you’re tall, probably your legs are longer and you’re a faster walker. I’m a 5’ 8" man with a 30" inseam. Almost exactly average. You’d think the sensors would be aimed at the “average” person, yet I constantly have to pull up short in mid-stride as I approach the door at my favorite grocery store. I’m sure it’s the aiming, because I don’t have this problem _entering_ the store through this door - only exiting. I do walk faster than the average goober, though. “Mosey” is not in my repertoire. [Previous page](https://boards.straightdope.com/t/door-opener-at-grocery-store/312539.md?page=1)