Sitting in rush-hour traffic on I-5 to Vancouver got me thinking: Has anyone done a study to see if the cars stuck idling in non-high-occupancy vehicle lanes actually produce more emissions than the HOV lanes save? Or does everyone just assume that car pools = less pollution? 

—Mark L.

The extant research on HOV-lane efficacy tends to fall into one of two categories: (1) studies by people who love HOV lanes, which conclude that the lanes are a unicorn ride to God's pool party, and (2) studies by folks who hate HOV lanes, which conclude that the lanes cause baby cancer.

Still, any northbound traveler who's watched free-flowing traffic near the Columbia River Interstate Bridge freeze up at the stroke of 3 pm (when the left-hand lane becomes HOV-only) can be forgiven for joining the baby-cancer camp. Look at all these idling cars! If they'd just open that lane to everybody, we'd all be home by now, with a net carbon gain to boot!

The problem with this line of reasoning is something traffic engineers know as the law of congestion: The more lanes you open up, the more motorists will want to make the (now easy and fast!) trip, until, pretty soon, traffic is moving just as slowly as before—except now, there's more of it.

It seems people have a fixed amount of traffic-based suffering they're willing to endure, and by God, they'll drive as many miles as it takes to reach that level of misery. So HOV or no HOV, CRC or no CRC, we're all screwed.

If there's a villain, it's your a-hole boss for making you come to work all the time. According to the Telework Institute (cue the unicorns), 50 million Americans could be telecommuting; currently only 2.3 million are. That would save a lot of trips. Plus, hey—naked sales meetings!