Implementing variable mandatory speed limits on four lanes with the optional use of the hard shoulder as a running lane resulted in a 55.7 percent decrease in the number of personal injury accidents on a major motorway in England. METHODOLOGYA safety analysis of the implementation of a four-lane, variable mandatory speed limit operation (4L-VMSL) and optional use of the hard shoulder as a running lane used a before/after… Content type Benefit Date Posted 11/14/2011 Taxonomy (ARC-IT) Variable Speed Limits (TM20) Geolocation links England