For months, Uber has denied that it has any interest in becoming a private alternative to public transportation. Its latest announcement, though, certainly suggests otherwise.

Uber is piloting a new feature called UberHop in Seattle, in which multiple riders who are traveling a similar route are paired with the same driver. These riders are given directions to a pick-up location and a time when the driver will arrive. The rider will be expected to walk a little ways to the pick-up location, as well as to their final destination from the drop-off location. This appears to be modeled on the discounted "Smart Routes" Uber was testing in San Francisco earlier this year. And much like other features Uber is testing, Hop is a service that closely mimics a public bus.

"Investment in mass transit is an important part of the solution," Uber writes in a blog post Tuesday. "But it's expensive and not everyone lives within walking distance of the subway or a bus stop. Uber helps use today's existing infrastructure more efficiently at no extra cost by getting more butts into the backseats of fewer cars."

"More butts into the backseats of fewer cars."

Uber is also piloting its Commute feature in Chicago. Car owners interested in picking up a few fares on their commute to and from work can share their routes, as well as driver's license, with Uber to sign up. Uber would then pair those drivers with other commuters going in the same direction. This follows the company's announcement of the the new "destinations" feature it added to the driver-facing version of its app in San Francisco.

Uber says it chose Chicago because of the Windy City's problem with congestion. "I-90 recently earned the title of the ‘nation's worst bottleneck,' costing area residents 16.9 million hours of wasted time and a staggering $418 million in lost productivity per year," Uber notes.

Uber is billing both pilots as building on its goal of promoting the "casual carpool." Half of Uber rides in San Francisco are through the Pool feature. Uber also claims that in LA, UberPool "cut the number of miles driven across town by 7.9 million and prevented carbon dioxide pollution by 1,400 metric tons."

Travis Kalanick's dream is for a "perpetual ride."

But these features also feed into larger, more complex goals of Uber. As people move to cities, and mass transit gets more congested, Uber is seen as positioning itself as the guileless alternative. CEO Travis Kalanick has discussed the concept of "the perpetual trip" for Uber drivers, with pickups and drop-offs synchronized in such a way so that a driver's car is never empty.

A big unanswered question, though, is how much this is costing Uber. When a rider selects the Pool option, but the driver fails to find another fare, Uber covers the difference between the discounted and regular fare. The company is reportedly burning through money faster than it can earn it, which may explain recent news like another multi-billion-dollar round of financing.