Abstract
Roads 3-7 m wide are painted in Sweden with centre lines and intermittent edge lines. Most of traffic occurs inside lines, and in the dark visibility of edge lines may be bad. To improve visibility, line should be made continuous, but this would restrict traffic inside lines. Where should edge lines be placed ? Before and after studies were made on test sections with continuous and on control sections with intermittent edge lines. Speed was consistently higher on test than on control sections and it increased from before to after. Tests were repeated after 1 year. Continuous edge lines combined with increased road width appear to have produced favourable results.