In a significant move for automotive enthusiasts and advocates of alternative transportation, Colorado Governor Jared Polis has signed HB25-1281 into law, officially legalizing kei vehicles on the state’s public roads. The law, passed with bipartisan support, establishes the legal framework for titling, registration, and use of these compact Japanese imports, with the regulation set to go into effect on July 1, 2027.
What Are Kei Vehicles?
Kei vehicles, short for kei-jidōsha (or “light automobiles” in Japanese), are a class of ultra-compact cars, trucks, and vans defined by strict limits on size and engine displacement. Originally designed for urban efficiency in Japan, these tiny vehicles must meet criteria that restrict engine size (typically under 660cc) and overall dimensions. Though never sold new in the U.S., they can be imported under the 25-year import rule, which exempts them from modern safety and emissions standards.
Examples of beloved kei models include the Suzuki Cappuccino, Honda Acty, and the quirky Autozam AZ-1.
Sensible Rules for Small Cars
The newly signed law includes common-sense stipulations to keep kei vehicles operating safely within Colorado’s unique geography. Chief among them is a restriction against driving these low-powered vehicles on roads with speed limits exceeding 55 mph. With Colorado’s high elevations and steep grades—especially around I-70—this measure is a nod to practical performance limits.
Kei vehicles will also be exempt from standard dynamometer-based emissions tests. Instead, they’ll undergo a two-speed idle test, a static method typically used on pre-1982 vehicles, ensuring older imported keis can meet environmental requirements without complex retrofitting.
Additionally, HB25-1281 formally categorizes kei cars as motor vehicles under Colorado’s Uniform Motor Vehicle Law and Certificate of Title Act, granting them full legal recognition after years of uncertainty.
A Rollercoaster Journey to Legalization
Colorado’s stance on kei vehicles has shifted in recent years. A controversial 2024 proposal from the Department of Motor Vehicles aimed to ban kei and other “non-traditional” vehicles altogether, leaning on guidance from the American Association of Motor Vehicle Administrators (AAMVA). The DMV later walked back the proposal, but the lack of clarity caused registration issues for many would-be kei drivers.
Many enthusiasts found themselves in legal limbo—able to obtain temporary plates but unable to complete registration due to emissions hurdles in urban counties. Meanwhile, in rural counties with no emissions requirement, keis quietly motored along unbothered.
Growing National Movement
With this bill, Colorado becomes the 30th state to officially permit kei vehicles on public roads. While states like Texas, Florida, and California already allow keis with minimal restrictions, others impose severe limitations. For instance, New Hampshire allows use only within a 25-mile radius and on roads with a 35-mph limit. States such as Connecticut, Georgia, and Oregon continue to ban their registration outright.
Governor Polis encouraged other states to follow suit: “We’re excited in Colorado that now Coloradans have another vehicle choice. I hope other states join the club.”
Final Thoughts
Kei vehicle legalization in Colorado marks a victory not just for niche car collectors but for vehicle diversity, sustainability, and freedom of choice. With sensible regulation, Coloradans can now enjoy the charm, efficiency, and fun of Japan’s iconic mini-cars—legally.
And come 2027, expect to see a few more tiny cars zipping through your local streets.
