"Yet 45 years after the National Transportation Safety Board first recommended such a system, the technology, known as positive train control or PTC, operates only on a tiny slice of America's rail network - including a segment of the Metrolink commuter rail line in Southern California, which has become a leader in adopting the technology after a crash near Chatsworth (Los Angeles County) killed 25 people and injured 102 in 2008. It is also coming soon to Caltrain in the South Bay and on the Peninsula."

Lets see - 45 years ago was 1969 and I don't recall anything like today's PTC being available. True, there was ATS and CCS, but that isn't PTC. Metrolink and CalTrain are both government agencies, so they are paid for by grants that are paid for by taxpayers. I seem to recall hearing that without BNSF's help Metrolink wouldn't be even close to a PTC system.

"The technology monitors and controls train movements with a digital communications network that links locomotives with control centers. It's designed to prevent collisions by automatically slowing or stopping errant trains that are going too fast, miss stop signals, enter zones with maintenance workers on the track or encounter other dangers."

I was in elementary school, and don't recall anything being digital being available. I don't recall getting my first calculator (took 2 9v batteries and did not fit in any pocket) until around 1975. "It's designed to prevent collisions ..." - it may be designed to prevent collisions, but it won't eliminate them. It will add its own hazards due to its complexity and presumed reliance upon it. Think I'm wrong - how often does your computer freeze up? Most commercial software now just accepts that there will be errors, bugs and glitches that will be fixed eventually, and what if someone hacks into the system that train's are relying on for main track authority? Anyone remember the DEW line? Remember when GPS was intentionally scrambled to reduce accuracy by the military just a few years ago? And if sunpots/solar flares or bad guys take out the GPS system ....

"Since last year, 10 oil trains have derailed in the U.S. and Canada, including the catastrophic wreck a year ago in Quebec that killed 47 people in the small town of Lac-Mégantic."

Problem - I don't think Lac-Mégantic would have been prevented by PTC -most likely it was caused by the failure of the engineer only train to properly secure unattended equipment, a lack of qualified management, and oil that was more volatile than indicated by its shipping papers (no doubt the refineries knew exactly what was in Bakken crude). And is Canada requiring a compatible PTC system? Of the 10 derailments suggested, how many would properly working PTC have actually prevented?

"Congress and the Federal Railroad Administration are proposing delays in PTC deadlines, but the report last month from nine California agencies recommended just the opposite: accelerating the installation."

California can wave their magic wand and PTC will magically appear. All the electronics for the systems will be instantly delivered, properly installed and tested, and all the radio spectrum that Congress forgot to allocate will be available. Isn't one of the reasons the FRA is willing to consider a delay is because they don't have near enough qualified inspectors to certify the PTC equipment and railroad installations?

"In 1993, the Association of American Railroads prepared a 91-page study that laid out a case for benefits of the technology beyond avoiding wrecks: savings in fuel and labor costs, better traffic control, a means to monitor the condition of locomotives and "a better-rested and safer workforce." "

Better-rested? Can it make toast and do my laundry too?

I agree that a properly working PTC system will help prevent accidents and save lives. Do we have a properly working system readily available for nationwide installation? And how often will the obsolete electronics have to be replaced. Our cell phones are obsolete within a year or less.