I’m guessing that goes double (as it were) for a tractor pulling **two **trailers. Those are scary.
Many of the late model trucks use a diesel injection system in the exhaust to superheat the catalytic converter and burn off ash in the exhaust system. The hose leading to the injector has been known to brake on several occassions and spray fuel on a super hot exhaust system. The witness claimed to see fire comming from underneath the back of the cab, this is where flames would first be visible if this fuel line were to break.
On a trucks air brake system they use spring brakes that will employe if the truck experiences a loss of air pressure. These brakes are not strong enough to lock up the wheels on a loaded vehicle.Got a cite for that? I’m in the bridge end of the road business but I spend a whole lot of time with FHWA regulations and I’m unaware of any mandating a center median barrier. Of course, I could be mistaken so a cite would be appreciated as I’m unable to find such a regulation.
I didn’t find a mandate just a study done by California DOT: www.dot.ca.gov/hq/traffops/saferesr/Median-Barrier.pdf
Look at Figure 7-12: Freeway Median Barrier Study Warrant
The federal investigation man on TV said the federal mandate for freeways is 50’ and under for a center barrier. Hwy 5 is a US highway so I just took his word for it.
I found this on yahoo, but you will have to ask AP where they got their information:http://news.yahoo.com/california-fatal-bus-crash-fedex-truck-cargo-involved-221140524.html
Could be… Or a sideways expulsion of air at the force that a hovercraft’s air cushion runs on — as I indicated that will not be invented.
Prolly for the same reason’s this chap’s 1961 patent for an air cushion vehicle never took off.
It’s a shame what happened to hovercraft.
Barriers aren’t automatically required when the median is less than 50 ft wide – it depends on traffic volumes. If you look at Figure 7-12, for a median width of 50 ft a median barrier is considered at traffic volumes greater than around 42,000 vehicles/day (average daily traffic, or ADT). If your ADT is less than that, you don’t require a barrier based on the volume-width warrant. The crash location has a median width of 60 ft and an ADT of 25,000 veh/day. If you plot those values on the chart you’re well into the white where a median barrier isn’t required.
I figured out some of what they were talking about this afternoon. The median width at this location is 60 ft wide. According to Figure 7-12, a 60 ft median triggers a median barrier investigation at about 50,000 ADT, so that’s where the 50,000 veh/day I’ve seen bandied about comes from.
I’m still not certain why 50 ft is being quoted. I’m involved in the roadway safety end of things and I’ve never heard that figure before.
One witness who seemed to be credable stated the truck had fire comming out from under the cab before the collision. They seemed to dismiss this because they saw no signs of fire in the road or on the median leading up the crash. I would be looking at the fire issue closer if I were them. I worked on those trucks and know they have had issues with fires. The fire will be seen right where the lady says she saw it.
The car in front of the bus saw it on fire, but a man mowing his yard right next to the freeway saw the whole thing and said he didn’t see any fire.
You would think someone saw something that’s still alive … sometimes people are just afraid to get involved.
One of the students who died was last seen helping others out of the bus.
Something the NTSB said they would be looking into was whether the bus windows were properly marked, as it was a new bus and every window was designed to be an emergency exit. Everyone next to a window with their wits about them should have been able to pop it out and escape. But were they told that before embarking? Is the driver required to give a safety instruction speech like they do on airplanes? (they should) It also had seat belts, which no one was using.
Magnetic strip technology has been with us since the late 70s.