A claimant with medical benefits is also entitled to submit for mileage reimbursement. Trips to the doctor, the therapist and anything related to medical treatment/evaluations also can mean mileage going and coming. When you track it then it usually can be submitted for reimbursement. It is best to submit on a monthly or semi-monthly basis and not let it accumulate. Wait too long and reimbursement can be questioned though it can also be disputed at any time. Usually the insurer reviews the mileage and reimburses using a set rate. That rate can be seen here in this link.
Be realistic in your miles (some insurers use mapquest.com to calculate your miles) because excessive miles can make the insurer question even more about your case. Also mileage checks can take some time to compute and issue so do not think you will be quickly paid. Give it a month to six weeks.