Two seniors, do I double the fare?

No, the estimate is for the ride, regardless of how many passengers

Hi George,

The fares displayed on RideGuru, as well as inside the Lyft and Uber apps, are for the trip and not for each passenger.  This means that for the two of you, it will be the same price.  The fare is the same regardless of how many passengers you have, as long as all of you can legally allowed in the vehicle.

For some taxi companies, there may be a per passenger fee for riders more than 1 or 2 people.  However, this fee is usually very little. ~$1.

Exception: Uber and Lyft both offer carpooling options called UberPool and Lyft Line.  With these, you can only bring one friend with you for no additoinal cost. 

ippei 1202

Uber Driver, CEO of TaxiFareFinder and Unleashed, LLC