Personal injury claims could be heard in a new specialist court under plans to overhaul the civil justice system.

New summary sheriffs would deal with lower-level civil and criminal cases, under proposals in the Government's courts reform consultation. It has been described as the largest change to Scotland's courts structure in a generation.

The move could slash the legal costs of bringing a claim by two-thirds, with the bill for a three-day hearing likely to fall from around £30,000 to about £10,000.

There are concerns it may lead to more "ambulance chasing"-style firms encouraging people to make speculative claims following the boom in cases.

A key proposal is increasing the threshold under which the sheriff court can deal with civil cases from £5,000 to £150,000. This would free up the country's top civil court, the Court of Session, to deal with the biggest cases. It would mean two-thirds of about 5000 annual Court of Session cases will be moved to the sheriff courts and to a new specialist injury claims court in the Sheriff Court building in Edinburgh's Chambers Street.

Claims can still be raised in any sheriff court and Glasgow lawyers are looking to set up a system similar to the proposed central office in the capital.

Inefficient and outmoded practices and equipment in the criminal justice system are estimated by Audit Scotland to be wasting up to £55m every year.

Initial investment will be needed but changing the system, which would be running after 2015, should be cost neutral and result in long-term savings.

As 98% of Court of Session cases never reach proof hearings – being settled beforehand – the claims being transferred to the sheriff court are described as "paper cases" and so it is envisaged sheriffs and the specialist personal injury sheriffs will not be overburdened.

The sheriff court system also generally moves less slowly than the Court of Session. There will no extra judicial posts in the sheriff courts, but numbers of Court of Session judges may reduce. Government advisers said they did not believe the drop in cost would lead to an increase in personal injury claims.

Summary sheriffs would take over from full sheriffs and be on a lower salary, dealing with minor cases, while full sheriffs will also still be required.

It follows recommendations by the now Lord President Lord Gill, head of the judiciary, who published a major review of the civil justice system in 2009.

Justice Secretary Kenny MacAskill said the reforms "will help us ensure the right cases are heard in the right places and reduce unnecessary delays, cost and bureaucracy".