"You may not use the Uber API in any manner that is competitive to Uber or the Uber Services, including in connection with any application, website or other product or service that also includes, features, endorses, or otherwise supports in any way a third party that provides services competitive to Uber’s products and services, as determined in our sole discretion."
Here's one angle. If this app becomes popular and Uber sends a C&D, then Uber results will no longer show up in this app, meaning Lyft would get all the bookings from people who use it.
IMO that kind of term is anti-competitive and should not be legal. Uber markets itself as a free market alternative to the old cab monopolies, so why are they doing things like this?
I get the impression from the site that they have the fare rates, but are calculating distance and drive time using google maps and estimating the cost of the service. If this is true, they wouldn't need to use the API to run the site.
"You may not use the Uber API in any manner that is competitive to Uber or the Uber Services, including in connection with any application, website or other product or service that also includes, features, endorses, or otherwise supports in any way a third party that provides services competitive to Uber’s products and services, as determined in our sole discretion."
https://developer.uber.com/v1/terms/ under 2.A