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More on the Washington DC Metro Crash

Los Angeles Transit Officials Worried About Computer Problems Surfacing

2 min read
More on the Washington DC Metro Crash

Last night, the National Transportation Safety Board (NTSB) released more information about their investigation into this week's fatal Metrocrash. The NTSB said that:

"Investigators found metal to metal compression streak marks  on both rails of the track for about 125 feet ending near the approximate point of impact, consistent with heavy braking.

Investigators conducted tests at the accident site last night with a similar train and found that when the train was  stopped at the same location as the stopped struck train, the train control system lost detection of the test train.

Investigators have collected recorder data from the struck train. Data was recovered from eight of the nine recorders on the struck train. Data could not be downloaded from one recorder. Two of the eight recorders did not contain data related to the accident; data collection ended before the accident for undetermined reasons.

The operator of the struck train was interviewed earlier today. He said that he operated his train in manual mode during his entire shift that afternoon. He said that he saw a train in front of him and stopped to wait for the train to clear. While stopped, he said that he felt a hard push from behind."

In this morning's Washington Poststory on the crash, it stated that:

"If a malfunctioning circuit failed to detect the stopped train, it would have assumed that the stretch of track in front of McMillan's [the operator - ed.] train was clear and set the speed of her train at 59 mph, sending it hurtling into the stopped one."

The Metro board is not happy that the NTSB is releasing facts about the crash. The Post quotes Metro board chairman Jim Graham, who is a Washington DC politician, as saying:

" 'I believe it is very important to gather and determine the facts first and at an appropriate time release the facts," instead of "putting out piecemeal information, theories and possibilities" about the crash."

Well, he may be unhappy, but probably not as unhappy as transit officials in Los Angeles are right about now. It seems that major parts of the Los Angeles County Metropolitan Transportation Authority subway system use the same computer control system as the Metro. I suspect that they will be testing their rail sensors immediately.

The Conversation (0)

Why Functional Programming Should Be the Future of Software Development

It’s hard to learn, but your code will produce fewer nasty surprises

11 min read
A plate of spaghetti made from code
Shira Inbar

You’d expectthe longest and most costly phase in the lifecycle of a software product to be the initial development of the system, when all those great features are first imagined and then created. In fact, the hardest part comes later, during the maintenance phase. That’s when programmers pay the price for the shortcuts they took during development.

So why did they take shortcuts? Maybe they didn’t realize that they were cutting any corners. Only when their code was deployed and exercised by a lot of users did its hidden flaws come to light. And maybe the developers were rushed. Time-to-market pressures would almost guarantee that their software will contain more bugs than it would otherwise.

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