Most people forget you drive around in a moltov cocktail every day; Your gas tank is just as likely to get smashed, and could possibly be even MORE dangerous because gasoline will pour and stick around on the pavement for some time, and this is nasty if it's on you and it's burning. Hydrogen, on the other hand, will dissapate quite quickly if there's a tank rupture, and the tank itself will not explode (due to hydrogen exploding). I've tried to make propane cylinders explode in the past, and it's not as easy as you might think. If you shoot one, it will most likely just rupture and vent, even in the presence of fire (in my experience!). This danger is WAY overplayed in the media, especially concidering that car gas tanks are low-tech compared to the fuel cells used in race cars. (Fancy gas tanks, not real fuel cells:).
Remember that gasoline is stored at atmospheric pressure, and not at the high pressures required to have liquid hydrogen. A rupture in a tank will cause a rapid expansion of the gas to many times the volume of the car. The gas may dissipate fairly quickly, but if it ignites there could be a huge fireball.
Metallic hydrogen doesn't occur at any type of condition that would make it very convienient for storage. The high pressure means that there would still be the problem of a rapid expansion if the tank were to rupture. Using some type of porous zeolite to contain the hydrogen is a much more viable option.
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Ted Kennedy was in a plane crash, but that was back in the '60s.
Remember that gasoline is stored at atmospheric pressure, and not at the high pressures required to have liquid hydrogen. A rupture in a tank will cause a rapid expansion of the gas to many times the volume of the car. The gas may dissipate fairly quickly, but if it ignites there could be a huge fireball.
Metallic hydrogen doesn't occur at any type of condition that would make it very convienient for storage. The high pressure means that there would still be the problem of a rapid expansion if the tank were to rupture. Using some type of porous zeolite to contain the hydrogen is a much more viable option.