COMMERCIAL VEHICLE COVERING LAWS - UNITED STATES AND CANADA  
This directory lists the applicable laws of all states and provinces, which require the covering of dump trucks and motor vehicles with a tarpaulin or restrict the spillage of loads on the highways. The attached information covers data obtained through a survey conducted in the fall/winter of 2005 by the Truck Cover & Tarp Association of the Industrial Fabrics Association International (IFAI).

The general classification of each law appears next to the name of each state or province. These laws have been divided into four general categories by IFAI. 
A - Laws which require covering
B - Laws which require covering in limited instances
C - Laws which restrict spillage and require the secure fastening of loads and covers
D - Laws which restrict spillage only
 http://www.truckcover-tarp.com/index.php?option=com_laws&Itemid=19
Effective enforcement is the key to increased highway safety through dump truck covering. A strict law is sometimes not enough. In Missouri (category A), the law uses words like "shall have a protective cover," but the state police only enforce the requirement in extreme cases. In Connecticut and Georgia , on the other hand, strict enforcement of "C"-type laws has resulted in most dump trucks being covered. The motoring public in these two states is fortunate to have police who are especially concerned about the spillage problem. In most states "C"- and "D"-type laws are rarely enforced since the officer has to witness spillage before issuing a ticket. Effective enforcement is necessary with the strictest laws, but in the 38 states and provinces with "C" and "D" laws the police need clear guidance from the legislature if the public is to be protected legally, instead of just luckily. For information on how each law is enforced in actual practice, the state or provincial police should be contacted. Most officers are very cooperative in telling how and when spillage tickets are issued. 

NOTICE AND DISCLAIMER: The information contained provided was gathered by phone, fax and via web sites from each of state. These laws are subject to change. Consult local council for updated laws and regulations.