# Identify tool being used by highway worker **URL:** \ **Category:** Factual Questions\ **Created:** [November 8, 2019, 12:44am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156 "2019-11-08T00:44:20Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [November 8, 2019, 12:44am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/1 "2019-11-08T00:44:20Z")
A few weeks ago, there was a major traffic accident on a highway nearby my house (a gravel truck hit a car and toppled over). A few hours later, I was driving down that highway and spent some time stopped because several lanes were still closed. While stuck in the traffic, my wife and I saw a worker walking along the highway’s shoulder with a device I couldn’t quite identify. This was a hundred feet _before_ the accident (so the worker couldn’t have been looking at damage caused by the accident). The device looked a bit like a metal detector, but without the disk at the end. It did have what looked like an electronic display near the handle. Any idea what it could have been? ---
**Author:** ![harmonicamoon](https://avatars.discourse-cdn.com/v4/letter/h/65b543/32.png) [@harmonicamoon](https://boards.straightdope.com/u/harmonicamoon)\ **Post date:** [November 8, 2019, 12:58am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/2 "2019-11-08T00:58:46Z")
Probably a distance measurer. In the old days they had a wheel on the surface. But now they are digital, I guess. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [November 8, 2019, 1:00am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/3 "2019-11-08T01:00:14Z")
Best guess would be some sort of gas/fuel spill detector. ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [November 8, 2019, 1:01am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/4 "2019-11-08T01:01:35Z")
Cable detector? ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [November 8, 2019, 1:02am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/5 "2019-11-08T01:02:22Z")
> [@harmonicamoon](#): > > Probably a distance measurer. In the old days they had a wheel on the surface. But now they are digital, I guess. Could be. I wonder if he could see skid marks that I couldn’t and was measuring the distance from the beginning of the skid to the accident location? ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [November 8, 2019, 1:03am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/6 "2019-11-08T01:03:45Z")
> [@gotpasswords](#): > > Best guess would be some sort of gas/fuel spill detector. Don’t think so because he was at a location where the truck would have been well before the accident occurred (if he was trying to detect a spill, he would have been a ways down the road from where we saw him). ---
**Author:** ![kopek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kopek/32/337_2.png) [@kopek](https://boards.straightdope.com/u/kopek)\ **Post date:** [November 8, 2019, 1:11am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/7 "2019-11-08T01:11:54Z")
Some sort of detector; possibly even metal. Not all have the traditional loops we’re used to seeing. Some like this [![](https://armetaldetectors.com/wp-content/uploads/2017/02/whites-tm808-metal-detector3.jpg) ](https://armetaldetectors.com/wp-content/uploads/2017/02/whites-tm808-metal-detector3.jpg) are used a fair amount in road construction. It depends somewhat on which direction the construction was heading. Another kind you sometimes see looks more like this [![](https://i.ebayimg.com/images/g/H6AAAOSwJshdjdrc/s-l640.jpg) ](https://i.ebayimg.com/images/g/H6AAAOSwJshdjdrc/s-l640.jpg) and can work for non-metal pipes as well. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [November 8, 2019, 1:13am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/8 "2019-11-08T01:13:01Z")
> [@harmonicamoon](#): > > Probably a distance measurer. In the old days they had a wheel on the surface. But now they are digital, I guess. I’ve never seen a contactless distance measuring device akin to a trundle wheel. Around here, at least, the CHP either uses plain old steel tape measures or total stations, which are the digital evolution of a surveyor’s transit. Some jurisdictions use laser scanning, which captures enough data in a short amount of time to recreate an accident scene digitally. ---
**Author:** ![harmonicamoon](https://avatars.discourse-cdn.com/v4/letter/h/65b543/32.png) [@harmonicamoon](https://boards.straightdope.com/u/harmonicamoon)\ **Post date:** [November 8, 2019, 1:35am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/9 "2019-11-08T01:35:48Z")
> [@gotpasswords](#): > > I’ve never seen a contactless distance measuring device akin to a trundle wheel. Around here, at least, the CHP either uses plain old steel tape measures or total stations, which are the digital evolution of a surveyor’s transit. Some jurisdictions use laser scanning, which captures enough data in a short amount of time to recreate an accident scene digitally. The OP did not mention contactless. And I think if it was a distance measurer, CA would have the latest. And a laser would be a good choice. ---
**Author:** ![Banksiaman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/banksiaman/32/3334_2.png) [@Banksiaman](https://boards.straightdope.com/u/Banksiaman)\ **Post date:** [November 8, 2019, 6:46am UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/10 "2019-11-08T06:46:20Z")
This form of cable detector uses the ergonomic counter-weighting of the screen and grip, so looks like a metal detector without the dinner plate at the end: > **[SPX RD8100 Underground Pipe And Cable Detector Made in China - SPX RD8100...](https://www.electric-test.com/cable-locator/cable-and-pipe-locator/spx-rd8100-underground-pipe-and-cable.html)** > > Huazheng Electric Manufacturing (Baoding) Co.,Ltd is one of the leading spx rd8100 underground pipe and cable detector manufacturers China, welcome to import cheap and discount spx rd8100 underground pipe and cable detector from us. Is this what you saw? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 8, 2019, 12:21pm UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/11 "2019-11-08T12:21:38Z")
I think distance-measurers still use a wheel, but it might be a small enough wheel that the OP didn’t notice it. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [November 8, 2019, 12:36pm UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/12 "2019-11-08T12:36:39Z")
While I’m not saying this is the case, don’t discount the possibility that it was unrelated to the accident. I agree with others, they’re very possibly measuring distance, probably from the first point of impact or where they felt the driver lost control, but it’s also possible that it was just a DPW worker doing his job that he was going to do anyway. > [@](#): > > Don’t think so because he was at a location where the truck would have been well before the accident occurred (if he was trying to detect a spill, he would have been a ways down the road from where we saw him). Not if the driver said ‘yeah, about a hundred feet back my I went to hit my brakes and the pedal fell right to the floor’ or ‘…it sounded like I threw a rod’ or ‘…I could see in the mirror that my split rim separated’. ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [November 8, 2019, 10:49pm UTC](https://boards.straightdope.com/t/identify-tool-being-used-by-highway-worker/843156/13 "2019-11-08T22:49:52Z")
> [@Banksiaman](#): > > This form of cable detector uses the ergonomic counter-weighting of the screen and grip, so looks like a metal detector without the dinner plate at the end: > > [HZ-5000E Underground Pipe And Cable Detector Made in China - HZ-5000E Underground Pipe And Cable Detector Manufacturers - Huazheng Electric Manufacturing (Baoding) Co.,Ltd](https://www.electric-test.com/cable-locator/spx-rd8100-underground-pipe-and-cable.html) > > Is this what you saw? I think so, thanks. > [@Joey\_P](#): > > While I’m not saying this is the case, don’t discount the possibility that it was unrelated to the accident. I agree with others, they’re very possibly measuring distance, probably from the first point of impact or where they felt the driver lost control, but it’s also possible that it was just a DPW worker doing his job that he was going to do anyway. > Not if the driver said ‘yeah, about a hundred feet back my I went to hit my brakes and the pedal fell right to the floor’ or ‘…it sounded like I threw a rod’ or ‘…I could see in the mirror that my split rim separated’. Coincidence does seem likely.