When I lived in Moreton, a neighbour and I shared our cars with two other teachers who lived in Liscard. The four of us would go together into Liverpool dropping off at the three schools involved. My neighbour and I would take turns each week for two or three days to drive our cars.
Mostly it worked well but there were times when it broke down and I was left stranded waiting for my lift to arrive (remember we did not have mobile phones in those days). As my commitments grew it also became difficult for me to fit in with the timings and so, reluctantly I opted out and travelled on my own each day.
There was always the thorny issue of insurance because in the case of an accident, insurance companies then would not pay out if it could be shown that you were operating as a taxi – i.e. charging passengers for a lift.
Now I read that Orihuela has set up a car sharing scheme using an Internet database as a means of contact. The idea is that you simply enter your details i.e. the days, times you travel, the route, the number of available seats and the cost. Then people can choose to share with you and reduce both the cost of your journeys (most seem to be charging 1 or 2 Euros so that is not really significant) and perhaps more important, the environmental cost in terms of CO2 emissions.