Open Street Maps ''vehicle routing problem'' please read fullly

do not ask me ''what is your budget'' - if you ask me that, i will tell you my budget is $1.00 -- just tell me what it costs and i will compare prices and skill i will have a google sheet -- each row has a driver dropdown, an appointment time, a pickup address, and a dropoff address i need code in a database -- ''google geocoding'' for address coordinates - and then calculate driving distance and driving time between ''pickup to dropoff address'' and ''dropoff address to next pickup address'' i will sell this spreadsheet to transportation companies.. so possibly thousands of people will use a sheet, so the code from the db may receive 1-3 million driving distance and driving time requests per day-- so obviously google api wont work because it will cost my api $15,000 per day! i need to be able to calculate these on some free open source software -- and then ill just pay the cost of the google api request to my database which is almost free.