road hog 
noun informal
A motorist who drives recklessly or inconsiderately, making it difficult for others to pass.No worse specimen of the road hog has come under my notice than the well-to-do gentleman who drives a powerful car at high speeds on the present highways....
- ‘One of the things about Alejandro is he's a road hog and when he gets into these cities he gets involved in the local scene in some cases,’ Baekeland says.
- Drivers from this area are generally careful and courteous, and it is inevitably weekend visitors who drive like road hogs, park inconsiderately and despoil the beauty spots they visit.