Driving and Parking: Practice Questions & Explanations

Many states and municipalities restrict the routes hazmat vehicles may use, especially in densely populated areas, near tunnels and bridges, and through environmentally sensitive zones. The driver is responsible for knowing and following these restrictions. Tunnels are often prohibited or restricted (Class 1 explosives commonly banned, others requiring special permits) because a fire in a confined tunnel is catastrophic. Population centers, downtown business districts, and certain residential areas may also be restricted. Federal law also requires routing to avoid heavily populated areas, narrow streets, and other unsafe roads when alternative routes exist. Some materials (Class 7 radioactive in highway route controlled quantities, for example) require permits specifying the exact route.

Federal regulations require placarded hazmat vehicles to stop at every railroad crossing within 50 feet of but no closer than 15 feet to the nearest rail. The driver must look and listen for approaching trains, open the driver's window if practical, and proceed only when sure no train is approaching from either direction. The vehicle must not shift gears while crossing the tracks (avoid the risk of stalling on the tracks). This rule applies to all railroad crossings — those with active warning devices, those with passive crossbucks, and those without controls. The risk: a stalled or struck hazmat vehicle on tracks can result in a derailment plus a hazmat spill, a catastrophic combination. There are limited exceptions for streetcar tracks, abandoned tracks marked as such, and certain other situations.

Federal rules require placarded hazmat drivers to examine tires at the start of each trip and each time the vehicle is parked. A leaking, flat, or overheated tire on a hazmat vehicle is a fire risk that can ignite the cargo or release the contents. If a tire is found to be defective, it must be replaced before the trip continues. Use of the spare tire as a temporary fix is allowed within reason, but a damaged tire on a hazmat load cannot be ignored. The rule applies even on short stops and even at fuel stops. The walk-around and tire check that takes two minutes can prevent a roadside fire that ends careers and lives.

Parking a placarded hazmat vehicle is heavily regulated to limit consequences if the cargo leaks or ignites. The rules: do not park within 5 feet of the traveled portion of a highway; do not park within 300 feet of a place where there is an open fire or where people are likely to congregate (theatres, malls, schools, churches) — with exceptions for very brief loading/unloading. The vehicle must be attended at all times in some cases (Class 1 explosives, for instance) unless parked in a 'safe haven' specifically designated for hazmat overnight parking. Some materials require driver presence within sight and sound of the vehicle. Different rules apply to different classes; consult Section 9 of the FMCSA manual and 49 CFR Part 397 for specifics.

Shippers must provide emergency response information with every hazmat shipment. This includes a 24-hour emergency contact phone number staffed by someone who can speak knowledgeably about the materials. The information must travel with the shipping papers. In an incident, the driver provides this information to first responders so they can call the shipper's emergency line for technical guidance specific to the materials involved. CHEMTREC (1-800-424-9300) is a 24-hour service that can also provide chemical emergency information when the shipper's contact is unavailable. The Emergency Response Guidebook is responders' primary reference; the shipping paper emergency info is the technical specialist phone line.

Hazmat drivers do not have a different posted speed limit than other commercial drivers, but they must drive especially defensively given the consequences of any incident. Drive at a speed safe for conditions, well below the limit when conditions are adverse (rain, snow, fog, traffic), take curves conservatively, maintain large following distances, and avoid sudden maneuvers. A passenger-vehicle crash is bad; a hazmat crash can be catastrophic. The defensive driving philosophy applies even more strictly: leave yourself enough margin that another driver's mistake or a road defect does not force you into an emergency maneuver with a placarded load.

Following distance for hazmat vehicles should be larger than for general freight for two reasons. First, the vehicle is typically loaded heavily (gasoline tankers, chemical bulk loads) and takes longer to stop. Second, the consequences of being rear-ended into the vehicle ahead, or rear-ending another vehicle, are much greater — a fuel spill from a ruptured tanker creates immediate explosive fire hazards over a large area. The standard 'one second per 10 feet of vehicle length' is the floor; experienced hazmat drivers add another 2-4 seconds, especially in heavy traffic or adverse conditions. The goal is to give yourself enough time to slow gradually without panic braking, and to avoid being caught up in chain-reaction crashes ahead.

HAZMAT PARKING RESTRICTIONS protect the public by ensuring that vehicles carrying dangerous cargo are not left unattended in populated areas where a leak or fire could cause mass casualties. GENERAL HAZMAT PARKING RULES: (1) AVOID POPULATED AREAS: Never park within 300 feet of a bridge, tunnel, dwelling, or place of business unless necessary for delivery or receiving; this limitation is especially strict for Division 1.1/1.2/1.3 (most dangerous explosives), poison gases (Division 2.3), and poison liquids (Class 6.1, Packing Group I); (2) FLAMMABLES SPECIFICALLY: Keep away from open flames and sparks; minimize time parked near populated areas; (3) ATTENDED VEHICLES: Vehicles carrying certain Class 1 (explosives) and Division 2.3 (poison gas) materials in certain quantities must be attended at all times (driver within 100 feet and capable of moving the vehicle); (4) UNATTENDED PARKING: When parking a hazmat vehicle and leaving it unattended, the parking brake must be set and all doors should be locked; (5) REST AREA PARKING: Use of rest areas for hazmat vehicles is technically not prohibited but drivers should minimize time and ideally use truck stops where security and facilities are available; (6) FUELING: Must be attended when fueling — engine off, no smoking, remain present throughout. PERMIT-REQUIRED ROUTES: Class 1.1/1.2/1.3 explosives require pre-approved routes; driver must follow those routes even if GPS suggests alternatives.

TUNNEL AND BRIDGE RESTRICTIONS for hazardous materials are imposed by state and local authorities to protect infrastructure and the public from catastrophic incidents. MOST RESTRICTIVE: CLASS 1 EXPLOSIVES (Divisions 1.1, 1.2, 1.3) — the highest-consequence hazmat loads are the most restricted; many major tunnels (Lincoln Tunnel, Holland Tunnel in NYC; Baltimore Harbor Tunnel; etc.) are closed to explosives above very small quantities; some prohibit all Class 1.1/1.2/1.3 shipments; PROCESS FOR PERMITTED LOADS: Contact the authority controlling the tunnel (state DOT, port authority, etc.) in advance — not at the entrance; obtain written permit and any escort requirements; follow approved route (may require off-peak hours, police escort, specific lane); ROUTE PLANNING: Drivers must know tunnel restrictions on their planned routes; HazMat route plans (required for Class 1.1/1.2/1.3) specify approved crossings; GPS may not know all tunnel restrictions — paper route planning with verified crossing information is the professional standard; CLASS 2.3 (Poison Gas): Also restricted from many tunnels; OTHER CLASSES: Typically may use tunnels, but check local regulations for specific tunnels; some tunnels restrict flammables above certain quantities; VIOLATION RISK: Entering a restricted tunnel is a federal/state violation and risks permit revocation, significant fines, and — in a worst case — catastrophic incident responsibility.