Telegraph: Speed limits of just 15 miles-per-hour are to be introduced on major roads in planned new towns across the country as part of an effort to reduce global warming. Caroline Flint, the housing minister, will unveil the measure when she publishes planning guidelines later this week for up to 15 "eco-towns" across the UK, which will house 100,000 people. The Government wants the towns designed and built to encourage people to stay out of their cars. It will …