Why automakers fail to fix millions of recalled vehicles every year

Earlier this week, General Motors attempted to demonstrate how it's still safe to drive one of the 2.6 million vehicles it's recalled for ignitions that could shut off without warning, producing this video of a Chevy Cobalt going through various tests, and emphasizing that all will be OK if owners drive with only one key, and not the five-pound mass of key fobs and flashlights that now adorn many chains.

But based on trends in automotive recalls, many of the affected owners won't hear this, or anything else about the recall despite the congressional hearings and media coverage. If GM hits the industry's average for getting owners to bring their cars in for fixes, there would still be more than 500,000 vehicles on the road with a potential safety defect.

Call it the apathy hurdle. Vehicle recalls have become so common — with 632 recalls covering 22 million cars and trucks in 2013 alone — that a sizable number of owners simply don't care. Thousands will not be reachable by mail, which automakers must use as the official communications method for notifying them. And since many owners don't keep service records, there will be no way to know if a recall's been performed on a car when its sold; used-car dealers are not required to inspect for or make recall repairs before selling a vehicle.

Under federal law, automakers have to file quarterly reports on their recalls indicating how many of the affected vehicles actually get fixed. The National Highway Traffic Safety Administration's own data, like the chart shown above from a 2012 industry presentation, puts the recall completion rate for all vehicles at 77 percent, with passenger cars at 79 percent. Even if GM outperforms the average and gets 80 percent of the 2.6 million vehicles it's called back, that would still leave 540,000 unaccounted for.

To be fair, not all of those 2.6 million vehicles are likely still on the road. Many of them may have been built with the secretly upgraded ignition spring designed to fix the problem, a change GM engineers put into production without proper notice.

And other automakers have made sizable efforts to reach every owner affected by a serious problem. In the 1999 recall of Firestone tires on Ford Explorer SUVs, the companies aimed to replace all of the 6.5 million tires sold, running several ad campaigns and even calling customers directly. They came close — but seven years later, Firestone had to re-issue the recall because some 200,000 tires were still unaccounted for, mostly as spares.

Given the publicity generated by the GM recall, a higher than average number of affected owners should know to get their vehicles repaired. But if they don't, there's no backstop for whoever gets the keys next — and history suggests there will be thousands of such cases on the roads for years to come.