Overview [§397.2 and §397.3]
This section applies to all companies operating vehicles that transport hazardous materials requiring placards or marking.  Section 397.2 requires the company and driver to comply with the Federal Motor Carrier Safety Regulations (FMCSR) (49 Code of Federal Regulations [CFR] Parts 390-397, and Section 397.3 requires that the vehicle be driven and parked in compliance with the laws of the state or locality in which it is operated (unless the laws conflict with DOT rules, in which case the DOT rules must be followed).

Attendance [§397.5]
A driver must not leave unattended a vehicle loaded with hazardous materials other than Division 1.1, 1.2 or 1.3 (explosive), that is located on a public street or highway or on the shoulder of a public highway.  49 CFR §397.5 (more stringent rules apply to vehicles Division 1.1, 1.2 or 1.3 materials).  A vehicle is considered “attended” if the person in charge of the vehicle is on the vehicle, awake, and not in a sleeper berth, or is within 100 feet of the vehicle and has it within his field of view.  49 CFR §397.5(d)(1).  Thus, when making a delivery, a driver must not walk more than 100 feet from the vehicle or lose sight of the vehicle.

Parking [§397.7]
A vehicle containing hazardous materials, other than Division 1.1, 1.2 or 1.3 materials, may not be parked on or within five feet of the traveled portion of a public highway except for brief periods, when the necessities of operation (including delivery) require parking and make it unreasonable to park the vehicle in any other place.

Routing
With regard to routing of hazardous materials shipments, there are no specific federal requirements on how routes are to be selected, or which routes must be avoided.  However, many states do regulate routing.  The state rules generally indicate: “Unless there is no unreasonable alternative, a motor vehicle which contains hazardous materials must be operated over routes which do not go through or near heavily populated areas, places where crowds are assembled, tunnels, narrow streets, or alleys.  Operating convenience is not a basis for determining whether it is practicable to operate a motor vehicle in accordance with state and local regulations.”  A distributor who must deliver in a metropolitan area typically will always have vehicles that go through heavily populated areas; operating necessity, not operating convenience, will dictate that the vehicle travels heavily populated areas.  In other cases, the place of delivery will require that a placarded vehicle be driven through narrow streets or alleys.  Although the underlying reasoning of this routing principle is understandable, in practice the realities of dispatch and delivery make it essentially useless.

Fires [§397.11]
Additionally, Section 397.11 requires that a motor vehicle containing hazardous materials must not be operated near an open fire unless the driver has taken precautions to ascertain that the vehicle can safely pass without stopping; the vehicle must not be parked within 300 feet of an open fire.

Smoking [§397.13]
No one may smoke or carry lighted smoking materials within 25 feet of a vehicle containing explosives, oxidizing materials, or flammable materials, or an empty tank that was used to carry such materials.

Tires [§397.17]
When operating a hazardous materials vehicle that has dual tires on any axle, the driver must stop the vehicle in a safe location at least every two hours or 100 miles of travel, whichever is less, and examine the tires to determine if the tires are flat, leaking, improperly inflated or overheated.  If overheated, a tire must be immediately removed and placed at a safe distance from the vehicle, and the driver must not drive the vehicle until the cause of the overheating is corrected.  Flat, leaking or improperly inflated tires must be repaired or replaced at the nearest safe place (but a driver must not leave his vehicle unattended in complying with this provision).