Delaware’s roads have a strict rule you can’t afford to ignore. The Delaware 20 mph speed reduction requirement when passing vehicles with flashing lights is a legal obligation, not just a courtesy. It’s designed to protect emergency responders, roadside workers, and anyone stopped with hazard lights on.
As of 2026, this law applies statewide, and violating it can mean fines, points on your license, or worse. Here’s what you need to know to stay safe and compliant.
Quick Answer
The Delaware 20 mph speed reduction requirement when passing vehicles with flashing lights mandates slowing down by 20 mph below the posted limit. It applies to any stationary vehicle with active flashing red, blue, or amber lights. You must reduce speed in all lanes traveling in the same direction.
The rule covers emergency vehicles, tow trucks, and roadside assistance.
Why This Law Exists and Why It Matters
Delaware’s law exists to prevent accidents involving emergency personnel and roadside workers. According to the National Highway Traffic Safety Administration, hundreds of first responders are injured or killed each year in traffic incidents. This rule gives them a buffer of safety when they’re stopped on the side of the road.
The law also reduces the risk of secondary crashes. When drivers slow down, they have more time to react to unexpected obstacles or stopped traffic.
The Exact Rule: What Delaware Requires
Under 21 Del. C. § 4108, Delaware’s "Move Over" law requires drivers to slow down by 20 mph below the posted speed limit when passing a stationary vehicle with flashing lights. If it’s unsafe to change lanes, you must still reduce your speed.
The law applies to all roads, including highways and interstates.
The rule is absolute. There are no exceptions for heavy traffic or bad weather.
Which Vehicles Trigger the 20 mph Slowdown
The law covers a broad range of vehicles, not just police cars or ambulances. Here’s the full list:
- Emergency vehicles: Police cars, fire trucks, ambulances (red/blue lights)
- Tow trucks and roadside assistance (amber lights)
- DelDOT vehicles (maintenance, construction, or incident response)
- Utility vehicles (e.g., electric company trucks with flashing amber lights)
The key detail is that the vehicle must be stationary with active flashing lights.
When and Where the Rule Applies
This requirement is in effect 24/7 on all Delaware roads, including:
- Highways (I-95, I-495, US-13, US-202)
- State routes and local roads
- Parking lots and private property (if the vehicle is performing official duties)
The rule kicks in the moment you approach a qualifying vehicle. You must maintain the reduced speed until you’ve fully passed it.
Step-by-Step: How to Comply Safely
Spot a stationary vehicle with flashing lights ahead. Check your speed and the posted limit immediately.
Reduce your speed by exactly 20 mph below that limit. If you’re on a 55 mph highway, drop to 35 mph.
If you can safely change lanes, move over to create extra space. If not, stay in your lane but maintain the reduced speed until you’ve passed the vehicle completely.
What Happens If You Don’t Slow Down
Violating this law in Delaware carries real consequences. You’ll face a fine, typically between $100 and $200 depending on the court.
You’ll also get points added to your driving record. That can lead to higher insurance premiums and potential license suspension if you accumulate too many.
In the worst cases, failing to slow down can result in a collision. That means civil liability, criminal charges, or both.
Common Mistakes Drivers Make
Many drivers assume the rule only applies to police cars. It covers any vehicle with flashing lights, including tow trucks and utility vehicles.
Some try to speed up to get past the scene quickly. That’s illegal and dangerous.
Others forget to slow down in multi-lane traffic. The law applies to all lanes moving in the same direction, not just the one next to the stopped vehicle.
How Delaware’s Rule Compares to Other States
Most states have some form of a Move Over law. Delaware’s 20 mph reduction is stricter than many, which often just require slowing down to a "safe speed."
Some states mandate a lane change if possible. Delaware prioritizes the speed reduction regardless of lane changes.
A few states have no specific speed requirement. Delaware’s clear 20 mph rule removes any guesswork.
Real-Life Scenarios: When to Slow Down (and When You Might Not)
You’re on I-95 and see a state trooper with flashing lights pulled over on the shoulder. You must slow to 20 mph below the limit, even if you’re in the far left lane.
A tow truck with amber lights is assisting a broken-down car on US-13. The same rule applies.
If you’re on a divided highway and the flashing vehicle is on the opposite side, you don’t need to slow down. The law only applies when you’re traveling in the same direction.
FAQs About Delaware’s 20 mph Passing Law
Does the 20 mph rule apply if the vehicle is moving?
No. The law only requires slowing down for stationary vehicles with flashing lights.
What if there’s no safe way to slow down?
You must still reduce speed as soon as it’s safe. The law doesn’t allow exceptions for traffic or road conditions.
Are out-of-state drivers required to follow this rule?
Yes. Delaware’s law applies to all drivers on its roads, regardless of where their license is from.
Can I get a warning instead of a fine?
Possible, but not guaranteed. Officers have discretion, but the law allows for immediate fines and points.
Does this apply to private property?
Only if the vehicle is performing official duties. A security guard’s car with flashing lights in a private lot may not qualify.
Final Checklist: Are You Following the Law Correctly?
You’ve spotted a vehicle with flashing lights ahead. You’ve checked the posted speed limit.
You’ve reduced your speed by exactly 20 mph below that limit. You’ve moved over if it was safe to do so.
You’ve maintained that speed until fully past the vehicle. If you’ve done all this, you’re in compliance.
You’ve spotted a vehicle with flashing lights ahead. You’ve checked the posted speed limit.
You’ve reduced your speed by exactly 20 mph below that limit. You’ve moved over if it was safe to do so.
You’ve maintained that speed until fully past the vehicle. If you’ve done all this, you’re in compliance.
