"It would seem with the giant number of truck tires laying shredded on the road "in the U.S., such a system could be a sensible addition to truck fleets, yes?"
Not really, if you drive 2 hours on the same highway you may see two alligator backs laying along side the road, this is based on my own observations driving between San Antonio and Corpus Christi, TX
as well as between Dayton and Cincinnati, OH
. Both these stretches of road have many many many trucks passing through there every hour. A roadside call for a truck tire may cost anywhere from $350 to $500, sometimes more including the tire, depending on how bad the shop wants to stick it to you.
I used to work for a trucking company they operated 15 trucks all over most of the US. While these incidents did take place with a tire coming apart they were not by any means a weekly occurence, even more rare if you eliminate times when a tire is flat due to a nail, or the tire is replaced just because it has reached its replacement mileage. Also, tire dealers would be the first to tell you, sometimes tires just come apart regardless of the pressure inside and a new tire is as likely or even more likely than a recap to fail for no particular reason. Some of the engineers on here can figure out how much heat and stress a 22.5in low profile tire goes through running at 70mph all day every day if they are really curious.
The price the company I worked for paid for their International 9800i tractors was around $110,000, they are considered to have a 5 year useful life, at which time they should be fully depreciated and traded in on new equipment.
That price tag was without anything to measure the tire pressure. Say the tire pressure reading equipment cost an additional $500 per wheel initially (very conservative guess).. that is an extra $5000 per tractor, now we are talking $115,000 per unit, we haven't even considered the cost per trailer. Then we consider how often these things are going to break and the hours that it will take to fix them, remember, you have 18 of these thingies per truck moving down the road. When they do break that is time you both have to pay a mechanic and take the lost time from not moving. When you are not moving you are not making money. If these things would actually increase time on the road. great. However, it would have to be a pretty big time savings and I honestly don't see how it could be.
Without getting super nit picky, the economics do not make sense to put them on heavy trucks, especially considering how long some trailers sit without moving on drop lots. Brake lines, steel wheels, tires and other things corrode, deteriorate and have enough problems already without adding another expensive item to break, corrode, or fall off. An item which most companies would probably not bother to repair because the cost to add/fix this would not add any kind of real value to the asset and it would not cause a signifigant increase in revenue or resale value. Also, checking the tires before leaving on a trip, and if smart, at the end of every rest period is going to be just as good as messing with a new gadget that is really only going to tell you information you already know, that your tire is now flat.
When a large truck does have a flat they very rarely go skidding off the road, into the ditch, where they roll over, burst into flames, and possibly kill 300 people. On rare occasions blowouts do cause accidents but once again, that is the exception, not the rule. That is the short version of why Airliners need tire pressure instrumentation but trucks do not.
Things were better when it was two guys in a dorm room.