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.
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.
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.
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.
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.
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.