Your car’s ability to grip the road directly impacts your safety when driving. The laws of physics say that two objects cannot occupy the same space at the same time. Drivers can primarily be relied upon not to try to. But, when cars lose their grip on the road, drivers lose control of the vehicles. Then, all bets are off as to what they’ll hit.
Tires grip a dry road with a smooth rubber surface. However, our cars don’t always stick to dry roads. For example, ice and snow, even on a well-paved surface, can make traction unreliable. Furthermore, not all roads are well-paved. Rural roads of dirt or crumbling asphalt can be even more challenging in winter.
So, for the worst weather conditions, there are studded tires. Studded tires were once common in northern states. As both tire technology and the state of American roads has improved, they have grown less necessary.
There are still circumstances where studded tires may make driving much safer. Studded tires are not legal everywhere, and traditional studless winter tires are often a better choice (see our Snow Tires Guide for details).
In some circumstances, studded tires can confer a safety advantage. But they have limited applications and can offer less traction than studless tires in common driving conditions.
This guide will explain the pros and cons of studded tires and help you decide whether you might need them.
For a quick reference, find the answers to these common studded tire questions here plus a full list of state laws:
What are Studded Tires?
What are Studdable Tires?
How Do Studded Tires Work?
Where Do Studded Tires Work?
What is the History of Studded Tires?
What are the Advantages and Disadvantages of Studded Tires?
What are the State Laws Regarding Studded Tires?
Are Studded Winter Tires Right for You?
RELATED: Snow Tires Guide: All You Need to Know
What are Studded Tires?
Studded tires are to cars what cleats are to running shoes. They have small protrusions that dig into snow or ice to help a tire grip. Some tires have studs made from harder material than the tire, such as hard plastic or metal. In more modern studded tires, manufacturers form studs from tungsten carbide.
The studs are a permanent feature of regular studded tires, and their studs are not removable.
These studs are pretty small – generally protruding about 1/32 of an inch from the tire tread. With the car’s weight bearing down, they claw into ice and snow to provide extra traction as the wheel rotates.
What are Studdable Tires?
The term “studdable” signifies a middle step between studless winter tires and studded tires. To clarify, they have pre-drilled, threaded holes in their tread, designed to accept studs that drivers can add or remove as needed. Adding studs to studdable tires is time-consuming, as drivers must screw up to 120 separate studs into each tire. But they give drivers maximum flexibility to adapt to changing winter weather without an expensive trip to the tire shop to mount a new set of tires every time a change is needed.
To further explain, manufacturers make studdable tires with varying tread depths, so when you buy a set, you must purchase a matching set of studs that are designed to match.
How Do Studded Tires Work?
The studs in studded tires (or those added to studdable tires) break layers of ice on road surfaces and grip into the heavy snowpack.
But what exactly do studs look like? To clarify, studs generally have a large-diameter cylindrical root extending into the tire tread and a narrower, hard pin extending out of the tire that grips into ice and snow.
Aided by the car’s weight, they penetrate ice and snow as the tire rotates to grip in ways that studless tires can’t.
However, just as they pierce ice and snow, tire studs can pierce the roadway. They are illegal in many states and legal in only certain times of year or regions of others because of their damage to road surfaces.
Where Do Studded Tires Work?
Studded tires are most effective on unplowed roads and unpaved surfaces. Similarly, drivers that spend a lot of time on rural roads find them useful.
However, drivers who spend most of their time on well-maintained highways or paved urban streets can rob themselves of traction by using studded tires.
History of Studded Tires
Early History
The idea of using studded wheels for winter road-gripping predates the automobile. Some horse-drawn carriages in northern climates used studded wheels before the invention of the modern tire.
Inventors were experimenting with studded tires as far back as when cars became practical. For example, an article from a 1908 edition of the United Kingdom’s “Autocar,” the world’s first car publication, speculated whether towns would ban them to protect road surfaces.
As a mass-produced consumer product, Studded tires first appeared in Scandinavian countries in the late 1950s and came to the United States in the 1960s. They came to prominence in America, though, in the 1970s.
More Recent History
But the use of studded tires has faded as several other technologies have spread and improved. American roads have steadily improved in quality, and rural roads are far more likely to be adequately paved today than in the heyday of studded tires.
Additionally, ice plowing has also expanded to more streets and is no longer limited to highways.
Finally, the grip of non-studded winter tires has steadily improved. Thanks to continuous research by tire engineers, the non-studded winter tires of today provide reliable grip in much worse conditions than those of the 1970s, helping to close the performance gap with studded tires.
Studded Tire Advantages
Some form of studded tires is still the best solution in bad weather conditions. They grab substantially better on snow and ice than the all-season tires most cars wear when leaving the factory. They also grip better than studless winter tires on uneven or unpaved surfaces. Additionally, studless winter tires are not able to drive safely on unpaved dirt roads covered in snow. However, studded tires will.
Most importantly, studded tires are exceptionally safe in descending icy mountain passages. The studs dig into ice and snow and can keep a vehicle from sliding.
Studded Tire Drawbacks
One disadvantage of studded tires is that studded tires are only helpful on ice and hard-packed snow. However, the added grip of studs clawing into ice and snow is worth the added cost of studded tires.
On paved surfaces, whether dry or wet, studded tires actually provide less traction than studless tires. An uninterrupted soft rubber surface in contact with paved surfaces creates a high traction contact patch that gives your car a sure-footed grip. But studded tires have hard, smooth metal pieces interfering with that contact patch, making them less safe on plowed, paved roads.
In slushy or mixed conditions, any advantage conferred by the studs is minimal.
The truth is that studded tires damage paved surfaces. Many jurisdictions ban their use to protect road surfaces. These types of tires will carve ruts into roads where water will pool and freeze.
Finally, studded tires can be noisy.
Regulations by State
Some states ban studded tires entirely because of the damage they can do to roadways. For example, certain states allow them only during specific dates or on certain types of roads or vehicles.
States That Allow Studded Tires
At all times, the following states allow tires with studs in them.
- Colorado
- Kentucky
- New Hampshire
- North Carolina
- Vermont
- Wyoming
States That Don’t Allow Studded Tires
The list of states below ban studded tires year-round for all drivers.
- Florida
- Louisiana
- Michigan
- Mississippi
- Puerto Rico
- Texas
States with Studded Tire Restrictions
In 33 states, most drivers are allowed to use studded tires only during specific dates. Two states – Alaska and Maryland – restrict their use to certain counties or latitudes. Several states allow rural mail carriers, emergency vehicles, or those with disabilities who live in remote areas to use them.
Alabama, Georgia, and New Mexico allow studded tires when snow and ice require them, so drivers who install them must be prepared to encounter a law enforcement officer who disagrees.
Studded Tire Laws by State
| State | Law |
| Alabama | Allowed when snow and ice require them |
| Alaska | North of 60th parallel – Allowed September 16 – April 30
South of 60th parallel – Allowed October 1 – April 14 |
| Arizona | Allowed October 1 – May 1 |
| Arkansas | Allowed November 15 – April 15 |
| California | Allowed November 1 – April 20 |
| Colorado | Allowed |
| Connecticut | Allowed November 15 – April 30 |
| Delaware | Allowed October 15 – April 15 |
| District of Columbia | Allowed October 15 – April 15 |
| Florida | Not allowed |
| Georgia | Allowed only when snow and ice require them |
| Hawaii | Not allowed, except on the Mauna Kea access road above Hale Pohaku and on Mauna Kea Science Reserve |
| Idaho | Allowed October 1 – April 30. Fire departments may use them year-round |
| Illinois | Except for those rural mail carriers and persons with disabilities living in unincorporated areas may use them from November 15 – April 1. |
| Indiana | October 1 – May 1 |
| Iowa | November 1 – April 1 |
| Kansas | November 1 – April 1 |
| Kentucky | Allowed |
| Louisiana | Not allowed |
| Maine | October 2 – April 30 |
| Maryland | Allowed only in Allegany, Carroll, Frederick, Garrett, and Washington counties, November 1 – March 31 |
| Massachusetts | Allowed November 2 – April 30 |
| Michigan | Not allowed |
| Minnesota | Not allowed, except that rural mail carriers may use them during snow and ice November 1 – April 15 |
| Mississippi | Not allowed |
| Missouri | Allowed November 2 – March 31 |
| Montana | Allowed October 1 – May 31 |
| Nebraska | Allowed November 1 – April 1 |
| Nevada | Allowed October 1 – April 30 |
| New Hampshire | Allowed |
| New Jersey | Allowed November 15 – April 1 |
| New Mexico | Allowed only when snow and ice require them |
| New York | Allowed October 16 – April 30 |
| North Carolina | Allowed |
| North Dakota | Allowed October 15 – April 15. School buses may use them year-round |
| Ohio | Allowed November 1 – April 15 |
| Oklahoma | Allowed November 1 – April 1 |
| Oregon | Allowed November 1 – March 31 |
| Pennsylvania | Allowed November 1 – April 15 |
| Puerto Rico | Not allowed |
| Rhode Island | Allowed November 15 – April 1 |
| South Carolina | Allowed |
| South Dakota | Allowed October 1 – April 30. School buses and municipal vehicles may use them year-round |
| Tennessee | Allowed October 1 – April 15 |
| Texas | Not allowed |
| Utah | Allowed October 15 – March 31 |
| Vermont | Allowed |
| Virginia | Allowed October 15 – April 15 |
| Washington | Allowed November 1 – March 31 |
| West Virginia | Allowed November 1 – April 15. Air pressure must be 40 psi or below |
| Wisconsin | Except that emergency vehicles, school buses, and mail carriers may use them are not allowed. Vehicles registered in another state may use them if the car is in Wisconsin for less than 30 days. |
| Wyoming | Allowed |
Are Studded Winter Tires Right for You?
Whether studded tires make sense for you depends on where you live and the driving that you do. In most circumstances, studded tires are not necessary and may cause more problems than they solve.
On the other hand, if you live in an area with frequent ice or heavy snow, do much of your driving on rural or unplowed roads, and live in a place where they are permitted, studded tires may be worth the tradeoffs in cost and hassle.
Studless winter tires are a better choice, for example, if most of your driving takes place on paved, plowed roads.
