Everybody out of the pool: unpopular carpool rules are finally running out of gas.

• Author: Green, Kenneth

Back in 1990, the federal government picked up Reg. XV, a Southern California ridesharing regulation, and enshrined it in the federal Clean Air Act. The rule forced large employers in highly polluted areas to adopt programs that would induce their employees to "rideshare" using carpools or other alternatives to driving alone. Rideshare boosters promised not just cleaner air but less stress, lower costs, and increased camaraderie among commuters. Rideshare fairs and carpool posters sprang up like weeds as other polluted regions adopted clones of Reg. XV.

But ridesharing didn't work. Employees didn't want to abandon the flexibility and autonomy of driving alone. Employers had to offer a lot of costly incentives to get tiny increases in carpooling, producing tiny air pollution reductions at ridiculously high costs. Zealous air pollution bureaucrats created a morass of rules and regulations that dictated everything from the educational level of "employee transportation coordinators" to the rank of the company officer signing the company's pledge to support ridesharing.

One Southern California aerospace company spent more than $1 million a year to promote ridesharing and had to submit 23 separate plans detailing how this was to be done. One year, it was told to repaint all of its 45,000 parking spaces so it could assign "preferential parking" based on how often commuters shared rides. Regulators backed down only after the company demonstrated that union...