Truck ice missiles were the cause of several of the worst wrecks in the nasty winter storms in Pennsylvania this week - great lumps of ice shooting off the roofs of tractor-trailers. Unlike the incompetently managed PennDOT highways the pavement of the Pennsylvania Turnpike was kept clear by early salting and quick and repeated plowing. But that didn't protect it from ice missile attack.

Around 10am Friday near the US322 overbridge (MP270) near Brickerville in Lancaster County a lump of ice flew off the roof of a westbound tractor trailer and hit the windshield of an eastbound tanker truck causing the driver to lose control and roll over, according to a Turnpike spokesman. The tanker truck was carrying a common petroleum liquid - xylene, a flammable solvent and feedstock for the manufacture of polymers.

The wrecked tanker didn't leak or burn. But even so the Turnpike was closed for almost six hours since hazardous materials experts took charge. An empty tanker had to be found, brought to the scene and the contents of the wrecked tanker pumped, and the damaged vehicles removed.

The Turnpike was closed between Exits 266 (PA72) and 286 (US222), 32km (20mi). Many cars turned around, but the big rigs just had to wait. US322, an undivided surface arterial became the Penn Pike stand-in.

There were other reports of similar truck ice missile crashes on PennDOT's interstates though there the main problem was that they allowed snow and ice to remain and accumulate on the pavement where it was crushed and frozen into a rockhard overlay of ice. Normal snow plows mounted on dump trucks were helpless. The removal of PennDOT's ice overlay required the ripping teeth and heavier attack capabilities of construction graders - equipment not normally kept at the ready in the snow season.

Still PennDOT's problems were aggravated by ice missiles coming off truck roofs, and in at least one case, reports suggest, the resulting crash caused such severe backups that snow clearing had to suspended for hours because snow plows were unable to get in to work the pavement. That was when they started closing their interstates, pleading with the Turnpike to take the traffic they were unable to handle.

Gov Ed Rendell has called the state's handling of the snow and traffic on the PennDOT interstates "totally unacceptable" and appointed a group to review what went wrong. Thousands of motorists were trapped in their cars for many hours, some overnight, and they complained that PennDOT had no warning signs.

Penn Pike allows 3ft for roof ice

The truck height limit on the Penn Pike and most Pennsylvania interstates is only 13.5ft (4.11m) but most overhead signs and new bridges are set at 16.5ft (5.03m) overhead clearance. That 3ft (0.9m) extra is partly because of snow and ice on truck roofs.

Truck roof snow has long been an issue in Pennsylvania. The state has sufficient through truck traffic that hours-of-service limits cause large numbers of truckers to sleep overnight in their cabs at truckstops where a foot or more of snow can accumulate on the roofs of their trailers and tractors. Wind can cause it to drift to greater heights in places on the roof.

If it's cold dry snow it blows off harmlessly once they get moving. But if there's a mix of snow and freezing rain, or some melt and a freeze, while the truck is stationary then it binds together and becomes icy. Hence the occasional ice missiles that fly off randomly as they rumble along the highway.

E-ZPass antenna height was an issue

The 16.5ft (5.03m) clearance limit on the Pennsylvania Turnpike is apparently borne of decades of experience of roof ice. Back in late 2000 there was a confrontation between the Penn Pike and the IAG E-ZPass group and Mark IV over the 5.03m (16.5ft) limit for overhead equipment. Following its established standards the Turnpike set the E-ZPass antennas at 5.03m (16.5ft). Mark IV, the E-ZPass supplier, said it couldn't sign off on the installation in Pennsylvania because they were outside the approved and tested mounting height of 4.42m to 4.72m (14.5ft to 15.5ft). Antennas in NY, NJ, DE, MD, VA and elsewhere had all been set within this height range, and it was incorporated in the contract documents between the IAG and Mark IV.

Lawyers said that if the Penn Pike set its antennas at 5.03m (16.5ft) then they would be voiding their warranty on 99.95% accurate read rates.

21 out of an initial fit of 68 antennas had been set to 5.03m (16.5ft) before the issue was raised.

Brian Swett, program director for electronic toll collection held firm for the Penn Pike height, saying: "The (E-ZPass) antennas are not going to serve as the Turnpike's over-height detectors. We're not going to have a truck (with its ice and snow load) bringing down an antenna and shutting down the system." (Toll Roads Newsletter #51, Sept 2000 p51)

The E-ZPass antennas were protected, but not the windshields of other vehicles.

Ice missiles a research opportunity - COMMENT

20k to 25k heavy trucks/day use the Penn Pike, I-80 and I-81, and I-90 and I-78. In bad weather when car drivers stay home trucks can constitute the majority of the traffic - as the pictures show. The sheer acreage of truck roof space out there on the highways carrying ice makes ice missiles a hazard.

Some arithmetic: 150k heavy trucks per day on Pennsylvania highways with an average roof of 50ft x 8ft = 400ft2 a total of 60m ft2 or 1,377acres (557ha) by 6 inches of ice = 30m ft3 of ice =850k m3 at specific gravity of 1, (the beauty of metrics!)=850kt or about the weight of eight aircraft carriers - a large mass to have floating randomly around a state like Pennsylvania on truck roofs.

This week's truck ice missiles have inflicted such heavy casualties and economic losses there's surely a case for some research into how best to prevent trucks carrying dangerous roof ice onto the highways. There is no present program to prevent this.

The common law could probably be used against trucks bringing ice onto the highways - suing them for damages - but that doesn't seem to be working.

Do the major truck route highways need roof ice detectors - an overheight laser detector say - at the exits of truck stops and rest areas, or even on entry ramps?

How best to de-ice truck roofs before the trucks get on the roads? What are the alternative techniques for getting the ice off safely? Some of the big trucking companies must have techniques for cleaning trailer roofs in their yards?

Who should pay?

How to enforce?

ADDITION: Truckers forum discussion

A trucker's forum says legislation was passed last summer in Pennsylvania imposing a fine ranging between $200 and $2,000 for carrying ice on your vehicle which causes an accident. The truckers discussed it under "Heads up on a new PA law" as follows (edited slightly for conciseness):

Truckfam: I know it is hard to keep track of all laws, especially the new ones. The new law is that in winter you have to take all snow and ice off of your vehicle. If you are driving, and snow or ice falling off of your car, van, or truck causes an accident you can be fined from $200 to $2000. I don't know all implications for the big rigs. I don't really see how you can safely get off the snow and possible ice of the top of those trucks.

Mackman (Concordville PA): The truck I can handle but there's no way I'm getting snow or ice off the top of the trailer. Where do these people come up with these ideas

Part Time Dweller (West Chicago): They aren't saying you have to clean it off, just if if the snow/ ice from your trailer causes a wreck, you are going to get a ticket,which would be the least of you worries if it is a serious accident. The plaintiffs lawyers will make that fine seem like nothing.

Uturn2001 ( E Central Illinois): Yeah it is a real shame some fools have to follow so close to another vehicle to get hit by the snow and ice. :roll: :roll: :roll:

mapleleaf_1 (Wisconsin): PartTime I was just thinking about me cleaning it off and falling or hurting myself in some way. Then what do I do? Drive safe everyone. :)

Part Time Dweller (West Chicago): Uturn2001 wrote: Yeah it is a real shame some fools have to follow so close to another vehicle to get hit by the snow and ice.

Uturn, tailgating isn't an issue here. Ice sheets will fly off a trailer with with such force that vehicles 50 -100 feet back will get nailed. So will oncoming traffic if the wind is right. Been on the receiving end of the flying ice before.:shock Nice attempt on trying to pass it off on the 4 wheeler though. :roll:

Part Time Dweller: I wouldn't climb up there either, just now, a driver will get a ticket if flying ice or snow causes an accident. I guess after a motorist got killed in PA last year by flying ice, the lawmakers decided to pass a feel good law to make it appear to the general public that they are doing something about a 1 in a million accident.

WAVP375 (Charlotte NC): Feel good legislation - losing touch with reality.

Malaki86 West Virginia): I don't think PA could force a driver to clear the snow/ice from the top of their trailer. The reason, simple, the height. Because of the height of the trailer, OSHA requires safety restraints, as well as a chain around the edge to prevent you from falling.

Sgt_D (Texas): just hop in and out of New Jersey, they have 13'6" overpasses that will clean that off for you.

Shawnee (Canada): It has always been a law up here, One company I worked for had a device for removing snow, when you drove out the gate it would scrap the snow and ice off the trailer.

Part Time Dweller (West Chicago): Malaki86 wrote: I don't think PA could force a driver to clear the snow/ice from the top of their trailer... Again they aren't telling you to climb up and clean the roof off, they are just saying if ice/snow flys off your trailer, you will get a ticket. Unless every shipper/ receiver with drop lots and every terminal installs a roof scraper it is a moot point.

Malaki86 (WV): And because a driver can't be expected to climb on top of the trailer, i have a feeling that any lawyer worth anything would be able to get that ticket dropped. That'd be the same as writing tickets to someone because for going too slow in a posted area because the truck is governed below that speed.

Fredog: how do you prove which truck the ice came from to cause the wreck?

: thebaldeagle655 (Wichita Falls TX): Thank God I (1) pull flatbeds and (2), don't drive in Pennsylvania! Seriously though, I personally applaud Penn. for this law. Last week I was in Colorado going down Loveland Pass when another 18 wheeler, exceeding the speed limit by about 30 miles per hour passed me, a large sheet of ice flew off his truck and luckily hit my trailer, not my cab. No damage but it hit hard enough I could feel the truck jerk from the force.

Solution here? Truck washes are going to have to start performing an ice removal service. Since the weather is too bad for them to wash the truck they should be glad to add this service. As for the inconvenience of having to keep your truck safe for other drivers? Priceless!

A driver should not be complaining about this law, basically it is already federal law in that you are not allowed to drive an unsafe truck in the first place!

I know I will get a lot of flack on this one but we all need to take a positive look at this, not just look at the inconvenience it causes us. Any time we get ice, I do have to scrape the top of my flatbed. Granted it is not as high as the vans but I still have to exert a little effort. Unfortunately driving a truck does involve a little effort outside the cab occasionally!

Fredog: good idea, but the nearest truckwash to me is 130 miles, how do I get there? how about if all terminals and drop yards had to put in the overhead scrapers? if the trucking company was help responsible, it would make it worth their while to do it. perhaps truckstops could put them in too , yea right, that will happen

The full version at http://www.classadrivers.com/phpBB2/archive/o_t/t_23917/heads-up-on-a-new-pa-traffic-law.html

TOLLROADSnews 2007-02-17