Created by the Royal Society for the Prevention of Accidents (RoSPA), these codes also ask professional and trade associations, unions, local authorities, insurers, police and safety groups to sign up to the guidelines, covering respect for speed limits, driver fatigue and driver competence.
RoSPA's recommendations to employers include safe journey planning, banning drivers from powerful cars unless they can prove they have the correct skills and attitude to drive the cars safely, and limiting drivers to a maximum 350-mile round-trip if they also have work to carry out during the day.
For employees making a return journey, this would limit them to travelling between London and Hull or London and Cardiff. However, for a one-way trip, a driver could travel from London to Perth.
RoSPA developed the proposals as part of its campaign to improve safety among fleet drivers. An estimated 1,000 road deaths a year, along with thousands of injuries, involve at-work drivers making driving the country's biggest occupational safety problem.
Company car and van drivers have been shown to have a poor safety record, while statistics show those driving 25,000 miles a year as part of their job face almost the same risk of being killed at work as those working in mining and quarrying.
Roger Bibbings, RoSPA occupational safety adviser, said: 'Employers can no longer afford to avoid this vital safety issue. The Government's task force on work-related road safety has shown there is massive consensus for action.
'It is in the interests of every company to sign up to our codes. When driving to locations to carry out other work tasks, drivers should not normally be behind the wheel for more than 350 miles in a single day.
'If they are, we believe they will be too tired to be on the road and are likely to speed to get the job done.'
Other commitments in the codes include examining the benefits of black box technology for weeding out erratic drivers and persistent speeders.
RoSPA will discuss the codes as a seminar called The Practical Aspects of Managing Occupational Road Risk, to be held at Volvo Bus and Truck, Warwick, on June 18. The event is aimed at fleet bosses, transport operators, safety and human resources managers, insurance brokers and solicitors. Details are available on www.rospa.com/morr.