HAVERHILL, Mass Brandon Doyle, 26, had modified his 1995 Arctic Cat snowmobile in order to ride the machine on the road, by replacing its skis with wheels, police said. The snowmobile flipped on Primrose Street when he lost control. Witnesses said Doyle and his friends had been at a Memorial Day party. Police were investigating whether alcohol was a factor in the crash. Doyle was taken to Boston Medical Center with unspecified injuries. Police said witnesses told them Doyle’s friends tried to hide the snowmobile in a van after the crash.