Operational Effects & Safety Hazards Involved in Transporting 14-foot Wide Loads in Virginia

Report No: 76-R33

Published in 1976

About the report:

Since the early 1950's, highways have been designed in Virginia to carry 8-foot wide vehicles on 12-foot lanes. Extralegal width vehicles impose detrimental operational effects and safety hazards on other highway users. To minimize the hazards, the Highway and Transportation Commission places restrictions on the movement of all extralegal size vehicles through permit regulations. Currently in Virginia, frequent numbers of loads up to and including those 12 feet in width are allowed to be operated on the highway on a routine permit basis. Loads above 12 feet wide have been allowed infrequently, and only when alternative measures have been exhausted. Recently the Virginia Housing Study Commission endorsed a proposal to transport frequent numbers of 14-foot wide housing units on the state's highways. A 14-foot wide load exceeds the width of a standard 12-foot traffic lane and creates more hazards for the motorist than do 12-foot wide loads Based on studies of 14-foot wide loads conducted in California and Florida and by the Midwest Research Institute, and data obtained from the Virginia State Police and highway personnel, the significant findings of this study are: 1. Regardless of initial requests to have 14-foot wide loads traverse only the highest type roads, they must eventually traverse all types to reach their ultimate destinations. 2. An 18-foot traffic lane is needed for the safe movement of a 14-foot wide load. Thus, for standard 12-foot traffic lanes, encroachment by the 14-foot load onto the shoulder and the adjacent traffic lane is necessary. 3. Only 5% of Virginia's highway system mileage consists of 12-foot traffic lanes. 4. A 14-foot wide load could physically use approximately 45% of Virginia's highway mileage, provided traffic was restricted to a one-way operation. 5. Thirty percent of the highway mileage in Virginia consists of 7-foot traffic lanes that would physically restrict, if not preclude, the movement of a 14-foot wide load.

Disclaimer Statement:The contents of this report reflect the views of the author(s), who is responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Virginia Department of Transportation, the Commonwealth Transportation Board, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. Any inclusion of manufacturer names, trade names, or trademarks is for identification purposes only and is not to be considered an endorsement.

Authors

  • Martin R. Parker,  Jeffrey A. Spencer

Last updated: January 29, 2024

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