It’s not yet clear why Amtrak Northeast Regional Train 188 derailed Tuesday, killing eight and wounding over 200. Federal investigators say the train was traveling over 100 mph in a 50-mph zone in North Philadelphia, where the tracks take a sharp turn.

In other words, this would appear to be a story of human failure. But no matter what the inquiry yields, there almost certainly will be lessons about the United States’ negligent stewardship of its roads, rails, bridges and tunnels.

Amtrak long ago should have installed automatic safeguards against reckless driving on a route like the Northeast Corridor, which is heavily trafficked and passes through dense urban centers. The technology exists.

It is also astonishing that Amtrak appears to have no reasonable alternative travel route while this line is closed, badly snarling transportation between Philadelphia and New York.

Members of Congress were quick to promise help Wednesday. They can start by ending their perpetual neglect of the country’s infrastructure.

Their most basic task: Put the transportation budget on sound footing. The Highway Trust Fund relies on the federal gasoline tax to finance all sorts of transportation needs, but the revenue stream hasn’t covered the country’s spending requirements for years.

The obvious solution is to raise the gas tax, which has been at the same level since 1993. But neither President Obama nor Congress has the courage to say this aloud. Legislators are poised to continue their debate on second-best solutions. Instead, they should fix the problem now.

Meanwhile, Amtrak, which is budgeted separately, requires special attention. Top on the list would be more investment in Northeast Corridor rail service. Had Obama devoted his high-speed rail initiative to this corridor, instead of trying to sprinkle the funds across many states, something might have been accomplished by now.

Such steps do not lessen the burden of Tuesday’s tragedy. They might, however, prevent others.