Generally you will want to store as little as possible on Ethereum due to the cost. However with IPFS you will have to pin the data yourself or pay a service to do this. Ethereum will keep the data around forever until it is explicitly changed/removed. Currently each 32 bytes stored will cost you around $2 (plus another 2$ to send the transaction). So even storing just the IFPS URL on Ethereum is going to be expensive for this use case. (Assuming drivers/riders don't want to pay a 4$ overhead). I'm not aware of an easy way to verify and use IPFS data on-chain, so you would likely still need to save some of the ride information on-chain, adding to the above cost. (If you want the contracts to settle payments).