A handful of special-vehicle scenarios appear on every state DMV permit test. They're easy points if you've practiced them, and easy losses if you haven't.
Approaching emergency vehicles
When an authorized emergency vehicle approaches you with lights and siren, you pull to the RIGHT edge of the road and stop until it has passed. This applies even on the opposite side of an undivided road. On a divided highway with a physical median, only traffic on the same side as the emergency vehicle must yield. [Recommended driving resource]
Once the emergency vehicle has passed, stay back at least 500 feet from the rear. Tailgating an emergency vehicle responding to a call is a citable offense in every state.
Stopped emergency vehicles ("move over" laws)
Every state now has a "move over" law requiring you to change lanes away from a stopped emergency vehicle on the shoulder when you can do so safely. If you can't change lanes — heavy traffic, no adjacent lane — you must slow significantly, typically to 20 mph below the posted limit. The law usually covers police, fire, ambulance, tow trucks, and highway maintenance.
School buses
When a school bus stops with red lights flashing and the stop arm extended, traffic in BOTH directions on an undivided road must stop and remain stopped until the lights stop flashing or the arm retracts. On a divided road with a physical median (a barrier or a strip of grass — not just a center turn lane), only traffic on the same side as the bus must stop.
The fine for passing a stopped school bus is enormous in every state — often $500 to $1,000 for a first offense, plus mandatory court appearance and license suspension.
Funeral processions
A funeral procession is treated as a single legal unit. Once the lead vehicle has lawfully entered an intersection, the rest of the procession may follow even on a red light. You must yield to the entire procession — wait for it to pass before crossing the intersection — unless directed otherwise by an officer.
Slow-moving vehicles
A triangular orange-on-red "slow moving vehicle" emblem on the back of a tractor, buggy, or other equipment means it travels at 25 mph or less. Slow significantly behind one and pass only when the road is clear, straight, and posted as safe to pass. Never assume the operator has seen you.
Disabled vehicles
A vehicle stopped on the shoulder with hazard lights flashing is disabled. Move over a lane or slow significantly when passing — the same rule as for stopped emergency vehicles, in most states.
Animal-drawn vehicles
In rural and Amish-community areas, animal-drawn vehicles (buggies) are common and travel at 5-15 mph. The same SMV emblem usually marks them. Pass with extra clearance and be aware that the animal may startle at engine noise.