For decades, insurers have used such factors as age and credit score to determine the prices paid by individuals. Now many maintain that driving habits are a fairer gauge of a person's accident risk. In a deal announced early Thursday, Cambridge Mobile said it had closed on the purchase of TrueMotion for an undisclosed price. After combining, Cambridge Mobile is to provide telematics services to 21 of the 25 largest auto insurers in the U.S. based on premiums, with clients including some of the largest auto insurers in Australia, Canada, Japan, South Africa and the U.K. A pre-markets primer packed with news, trends and ideas. The deal paves the way for the two Boston-area firms to combine workforces to improve existing offerings sold to car insurers and invent new products.