A scientist discusses the issues that need to be solved for Americans to voluntarily carpool in larger numbers:

Maybe carpooling apps should let drivers set clear terms about the kind of behaviors they expect and encourage in their car, says Glasnapp. Maybe they permit conference calls and snacking, or maybe they’d prefer friendly, food-and-phone-free conversation. (Or total silence!) Riders should have the option to choose specific types of in-car experiences, too, with the understanding that the lower cost they are paying to carpool comes with a different set of expectations than does ride-hailing.

Technology has simplified the logistics of the rider/driver experience, says Glasnapp, but that sometimes comes at the expense of control. Most carpool apps offer specific time brackets during which drivers and riders can schedule rides—for example, on Scoop, morning trips have to be solidified by 9 PM the night before, and evening trips by 3:30 PM the same day, and matches are made after that deadline. That clarity is nice, says Glasnapp, but it’s almost too inflexible, since the system penalized him for making changes afterwards, and didn’t notify him if his ride offer had been accepted until after the cut-off. On the other hand, Waze operates its carpool system at any time of the day that drivers are on the road, which can be somewhat chaotic for riders’ expectations, says Glasnapp. The best carpool app will find a balancing point between structure and flexibility…

Finding the sweet spot for payment might be the most elusive goal for a great carpool system. Each app Glasnapp tested had their own approach to setting prices and payments for passengers and drivers: On Waze, riders pay a price that reflects the federal mileage reimbursement rate of $.54 per mile; this money is transferred directly to the driver. Lyft took the approach of setting flat fares, where carpool drivers earned up to $10, and riders paid anywhere between $4 and $10. Scoop pricing follows a similar model, and it also partners with local employers to provide discounted trips for riders, Glasnapp says. So long as drivers are still getting their cut, that’s an attractive strategy for all parties.

Even if the mileage rate is attractive on its face, though, the length of the journey has to match up to the driver’s expectation of fair compensation. If you’re already driving 40 miles to work, a request from a rider who is 17 minutes out of the way might require a pretty healthy compensation for you to accept—more than, say, the $10-and-under that a standard Lyft or Waze trip paid. “I think there is a magic number for every driver based on amount of inconvenience,” Glasnapp says. This is also sort of a chicken-and-egg problem—if there were more carpool drivers on the road, they wouldn’t be receiving such far-flung requests. But a great carpool app will need to nail the (highly individual!) question of pricing, so that more drivers want in.

A few other problems I could imagine:

1. The lack of personal space. Is there a way to design carpool vehicles where each person has this own compartment? This would cut down on the problems of differences in behavioral expectations and have the passengers and drivers not even interact or possibly even see each other.
2. Can everyone who wants to find someone to carpool with? I’m imagining it would be tougher for those with irregular work hours or who live in certain locations (or have unique paths). Would this be seen as a penalty for certain people for circumstances that may be difficult to control?
3. Is the answer necessarily an app?
4. The article suggests Americans have done this twice before – World War II and the 1970s Oil Crisis. This could be reassuring …or not. Might it suggest that Americans will only carpool when circumstances really demand it?