HS2 high speed railway trains could be made to run slower than initially planned to keep costs down. The government is to order the company building the project to consider lower speeds on the line from London to Birmingham, which has been hit by delays and cost overruns. HS2's chief executive Mark Wild was expected to say this month the line would not be completed until after the current 2033 deadline and it would cost over £100bn in today's prices, but that announcement has now been delayed until after the May elections. Transport Secretary Heidi Alexander is said to be weighing up all options to claw back as much time and money for the taxpayer as possible. Among the options is a lower initial operating speed on the line. HS2 has been designed to allow trains to run at up to 360km/h (224mph). Department for Transport sources point out that this is faster than any other conventional railway in the world.…