# I-10 in Texas... some wierd nagging questions. **URL:** \ **Category:** Factual Questions\ **Created:** [September 7, 2003, 10:48pm UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169 "2003-09-07T22:48:43Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Guybud5](https://avatars.discourse-cdn.com/v4/letter/g/d6d6ee/32.png) [@Guybud5](https://boards.straightdope.com/u/Guybud5)\ **Post date:** [September 7, 2003, 10:48pm UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169/1 "2003-09-07T22:48:43Z")
I just moved to San Angelo, Texas, from Monterey California. I notices as soon as I passed the TX border, I began to see signs on the side of the road saying “HC” in a circle. What is that? Also, along I 10 between El Paso and Fort Stockton, we kept seeing sections of 2 laned, two way highway that would randomly start and stop alongside the interstate. There were points where you could access the roads at the exits, and they were inside of the fence that runs alongside all interstate highways. At first I thought perhaps they’d just build the interstate alongside old 2 lane highways, and never bothered removing them, but they don’t seem decrepid, and they have fairly new roadsigns and lane markings. What’s up with these? ---
**Author:** ![whiterabbit](https://avatars.discourse-cdn.com/v4/letter/w/cab0a1/32.png) [@whiterabbit](https://boards.straightdope.com/u/whiterabbit)\ **Post date:** [September 7, 2003, 11:01pm UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169/2 "2003-09-07T23:01:09Z")
They’re access roads. I did most of my growing up in Texas and found it very odd when I moved to California to see that there weren’t any. They weren’t in Georgia either, but at least some stretches of freeway around here have them. I’m not sure of the rationale behind them, but this much I do know: they are a PAIN IN THE REAR when the traffic coming of the freeway does NOT have the right of way. In Texas, as far as I know, such traffic does. Here, it does not, and makes getting off onto access roads a challenge at best and scary at the worst. ---
**Author:** ![Yossarian](https://avatars.discourse-cdn.com/v4/letter/y/9de0a6/32.png) [@Yossarian](https://boards.straightdope.com/u/Yossarian)\ **Post date:** [September 7, 2003, 11:03pm UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169/3 "2003-09-07T23:03:11Z")
I think the “HC” signs mean that you are travelling along an approved “Hazardous Chemical” route. Along I-10 in west Texas (I lived out near Ft. Stockton for about 10 years), the frontage road is pretty random–AFAIK, it just is! Unlike many Interstates that did follow well-established older highways, much of I-10 through west Texas was built along a new route. Also, there’s not a hell of a whole lot of stuff out there that makes a complete frontage road necessary. ---
**Author:** ![Yossarian](https://avatars.discourse-cdn.com/v4/letter/y/9de0a6/32.png) [@Yossarian](https://boards.straightdope.com/u/Yossarian)\ **Post date:** [September 7, 2003, 11:05pm UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169/4 "2003-09-07T23:05:18Z")
More than you wanted to know about Texas Frontage Roads and the policy that guides their creation or not: [http://www.abilenecompplan.com/abilene\_comp/docs/FrontageRoad.pdf](http://www.abilenecompplan.com/abilene_comp/docs/FrontageRoad.pdf) (Warning–PDF.) ---
**Author:** ![Master\_Wang-Ka](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/master_wang-ka/32/3325_2.png) [@Master\_Wang-Ka](https://boards.straightdope.com/u/Master_Wang-Ka)\ **Post date:** [September 7, 2003, 11:17pm UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169/5 "2003-09-07T23:17:39Z")
I, too, believe that the HC indicates “Hazardous Chemical” routes. San Antonio, which is laced with various interstate highways, including I-10, I-35, and Loop 410, makes a big point of letting truckers know which highways may be used for hazardous chemical transport, and which may not. ---
**Author:** ![Mr.Ash](https://avatars.discourse-cdn.com/v4/letter/m/71c47a/32.png) [@Mr.Ash](https://boards.straightdope.com/u/Mr.Ash)\ **Post date:** [September 7, 2003, 11:37pm UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169/6 "2003-09-07T23:37:21Z")
“Hazardous Chemical” is right. The [Texas Highwayman](http://home.att.net/~texhwyman/geninfo.htm) has the following blurb: > [@](#): > > At one time, San Antonio was the largest metropolitan area in Texas, maybe the nation, that had no hazardous cargo routing plan. However, after a series of hazmat accidents near downtown, a plan was finally drafted. Due to objections from the City of Castle Hills which is bi-sected by Loop 410, one of the proposed hazmat routes, the plan had to be approved by the Texas Transportation Commision, which did so in June 2001. This map shows the adopted hazmat plan. Vehicles with hazardous cargo are completely banned from the red routes. Yellow routes are restricted to local deliveries only. Thru hazmat traffic must use the green routes. The plan has now been implemented with signs starting to appear on area freeways. The link above also includes the little green and white “HC” sign next to that text. ---
**Author:** ![Ringo](https://avatars.discourse-cdn.com/v4/letter/r/779978/32.png) [@Ringo](https://boards.straightdope.com/u/Ringo)\ **Post date:** [September 7, 2003, 11:54pm UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169/7 "2003-09-07T23:54:46Z")
IIRC, the HC routes are the result of Texas legislation that came in the wake of a traffic accident in Houston in 1976. A semi-tanker carrying anhydrous ammonia crashed through a sidewall of the freeway interchange of 610 and SW Freeway, plunging to the freeway below. Traffic was brought to a halt as a cloud of ammoniia gas seeped from the ruptured tanker trailer. The gas drifted back over the halted traffic, and was also picked up by the rooftop A/C of a nearby office building, where workers were unaware that anything was wrong. 6 died and 78 were injured, all but one from the gas. It was a horrific accident; almost anybody who was old enough and living in Texas at the time will remember it when it’s mentioned. ---
**Author:** ![lucky\_henry](https://avatars.discourse-cdn.com/v4/letter/l/bc8723/32.png) [@lucky\_henry](https://boards.straightdope.com/u/lucky_henry)\ **Post date:** [September 8, 2003, 12:34am UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169/8 "2003-09-08T00:34:53Z")
It actually stands for **H** Hazardous **C** argo, not just chemicals. ---
**Author:** ![Yossarian](https://avatars.discourse-cdn.com/v4/letter/y/9de0a6/32.png) [@Yossarian](https://boards.straightdope.com/u/Yossarian)\ **Post date:** [September 8, 2003, 12:41am UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169/9 "2003-09-08T00:41:34Z")
Sure, but really–isn’t _everything_ basically just a chemical? ---
**Author:** ![Road\_Rash](https://avatars.discourse-cdn.com/v4/letter/r/a8b319/32.png) [@Road\_Rash](https://boards.straightdope.com/u/Road_Rash)\ **Post date:** [September 8, 2003, 12:44am UTC](https://boards.straightdope.com/t/i-10-in-texas-some-wierd-nagging-questions/200169/10 "2003-09-08T00:44:23Z")
I was in Houston when that accident happened. The foliage was totally brown for about 1/2 mile all around the site for awhile. I’ve been told that it is Hazardous Cargo. Took me awhile to figure out what the signs meant.