6 Idaho Winter-Driving Rules That Get Drivers Ticketed Before the First Big Storm
It’s a cold morning in Idaho, you’re running late, and a shortcut feels harmless.
Some of those shortcuts can turn into a citation once the weather turns.
Here are the winter-driving rules that can get you ticketed before the snow even starts.
Note: This is general information, not legal advice. Traffic laws and fines are subject to change, so confirm the current requirements with the Idaho Transportation Department and the current fine amounts with the Idaho Supreme Court.
1. Leaving a Running Car Unattended
Leaving a running car unattended on a frosty winter morning can break Idaho Code 49-602.
You can’t let your vehicle stand unattended without first locking the vehicle if the engine is running.
It also requires you to set the parking brake and, on a grade, turn the front wheels to the curb or side of the highway.
So walking away from a running car at the curb with the doors unlocked breaks the rule.
The rule doesn’t apply to motor vehicles on private property.
East Idaho News reported in 2023 that it’s not uncommon to leave a car running as it warms up.
A peace officer can cite you for it under Idaho Code 49-1501, and Idaho Code 49-236 makes a chapter 6 violation an infraction.
The penalty for any Idaho infraction tops out at $300, with no jail time.
2. Studded Tires Out of Season
Idaho’s winter-driving rules put a calendar on your studded tires, which are legal on highways for only part of the year.
Idaho Code 49-948 bars studded tires on public highways from May 1 through September 30.
That leaves October 1 through April 30 as the legal window, according to the Idaho Transportation Department (ITD).
If you leave your studded tires on past April 30, a 2014 release called it a non-moving equipment violation with a $67 fine.
Psst! How much do you know about winter roads? Take our quiz and see if you can ace it.
Quiz
Winter Road IQ
Answer nine questions on snowplows, tires and winter driving. We bet you can’t get them all right. Prove us wrong?
Idaho State Police list which everyday household item among the things to carry in your car for emergency traction?
3. Wipers in Working Order
Winter driving puts your windshield wipers under Idaho Code 49-943, which lists snow among the things they have to clear.
Your windshield needs a device for cleaning rain, snow or other moisture.
That device has to be controlled or operated by the driver.
The statute also makes you keep your wipers in good working order.
Idaho Code 49-236 makes violations of chapter 9 infractions by default, so an officer can cite you for wipers that aren't in good working order.
4. Snow and Ice on Your Windows
Idaho State Police's winter tips tell you to clear snow and ice from all windows and lights, even the hood and roof, before you drive.
Idaho Code 49-612 makes part of that a legal requirement once the coating blocks your view.
The section covers a windshield or windows coated with ice, snow, sleet or dust.
The test is whether the coating blocks your view ahead, to the sides or to the rear.
Idaho Code 49-236 makes chapter 6 violations infractions, so a peace officer can cite that too.
5. Driving Too Fast for Conditions
On an icy road, driving too fast for conditions can break Idaho Code 49-654 even at the posted speed limit.
You can't drive faster than is reasonable and prudent under the conditions, given the actual and potential hazards.
Weather and highway conditions are among the special hazards the section names.
That means a speed that's legal on the sign can still be too fast on ice.
Idaho State Police's winter tips remind you that posted speed limits are for dry pavement.
Under Idaho Administrative Code rule 39.02.71, a 49-654 conviction carries three points.
ITD's point rules make it four points at 16 miles per hour or more over the posted speed limit.
Three points is a quarter of the way to a 30-day license suspension.
How the Point Count Adds Up
Idaho's violation point system tracks the points from each conviction on your driving record.
If you collect 12 or more points within 12 months, you face a 30-day license suspension.
Eighteen or more points within 24 months bring a 90-day suspension.
Twenty-four or more points within 36 months bring a suspension of six months.
When one incident brings several convictions, only the conviction with the highest point value counts.
6. Tire Chains for Commercial Vehicles
If you drive a commercial vehicle on Interstate 90 or state Highway 12, tire chains can be a legal requirement.
Idaho Code 49-948(5) lets ITD require tire chains at Lookout Pass, Fourth of July Pass and Lolo Pass when it finds a pass unsafe.
The department can require chains at those passes as weather warrants.
Idaho Code 49-236 makes chapter 9 violations infractions by default, so ignoring a tire chain requirement on those passes can get you cited.
Under Section 49-948(6), chaining up means a minimum of one tire on each side of one drive axle.
Each towed vehicle needs the same on an axle at or near its rear.
Section 49-948(9) exempts school buses and tow trucks, among other vehicles.
Plows and Road Reports
ITD has over 400 snowplows clearing and treating approximately 13,000 lane miles statewide.
Idaho 511 reports weather-related road conditions and road work on interstates, U.S. routes and state highways.
You can reach the service by phone, on its website or in its smartphone app, at any hour.
Bridges and overpasses are the first to freeze.
ITD's snowplows are 12 feet wide, and a 10-foot wing plow can extend to either side, so the safest place for you is behind the plow.
Idaho State Police add that the road in front of a snowplow is usually in much worse condition.
Its winter driving page also advises you to have a full tank of gas and windshield washer fluid before you head out in winter.
Four-Wheel Drive, Cruise Control and Skids
Four-wheel drive may help your vehicle get going quicker in snow, but Idaho State Police say it won't help you stop any faster.
Don't get overconfident in a four-wheel-drive vehicle, either.
ITD says cruise control can continue to accelerate your vehicle if you start to skid or slide, so don't use it on icy roads.
If you do start to slide, steer gently into the skid.
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