The Outback scheme is the brainchild of Brushford Private Hire and features the use of a specially adapted estate car.
The vehicle, converted with the help of a grant from the Countryside Agency, has a wider opening front passenger door and a swivelling front seat which pulls out over the door sill to make it easier for people to get in and out.
Director of Brushford Private Hire, Mike Clothier, said he hoped the new commercial service would make life easier for the region's elderly.
He said: "My experience working in a remote rural corner of Somerset convinced me that the elderly and disabled had a raw deal.
"I was determined to find a way to make transport and access to rural services easier. Often the most difficult part of a journey can be getting in or out of the car.
"So, with support from the Countryside Agency, guidance from Business Link Somerset, Somerset County Council and the backing of county and district councillors, we now have an answer - Outback."
Monday's launch will be attended by representatives from the Countryside Agency, district and county councils, Exmoor National Park Authority and Business Link Somerset.
The Outback estate seats up to four passengers and can be used to visit friends and relatives, for shopping trips and even for doctor and hospital appointments.