Destination X, by Nigel Raven

Struggling to stay the right side of sanity, Scott Reese thinks he is loosing his mind and cannot see a light at the end of the tunnel.
Scott’s weak mind is any easy prey for a desperate soul who possesses his body and mind, then takes his passengers on a journey they will never forget.
Despite Scott hating the children who make his job a living nightmare, there is still a small part of him left that stops him from picking up the school children and taking them to school on his bus.