State comparison · Updated October 2026
Illinois vs. Missouri Driving Laws (2026)
Illinois and Missouri differ on 5 of 9 topics we track: max speed limit, car insurance, car sales tax, car inspection and helmet law.
Heading from Chicago to Kansas City crosses the state line, and 5 of the nine rules differ once you cross. Main routes include I-90 on the Illinois side and I-70 in Missouri; the capitals, Springfield and Jefferson City, set the rules for each side.
The largest difference: the state tax on a $30,000 car differs by $608. Residents of Aurora who travel to St. Louis, or the other way around, live under both sets of laws: Illinois's on I-55 and Missouri's once they cross on I-44. Read the Illinois vs Missouri guide before driving from Chicago and Kansas City.
For a quick visit from Springfield to Jefferson City, pack a helmet and proof of insurance, set navigation ahead of time, and expect the limit to change from 70 to 75 mph after crossing.
| Topic | Illinois | Missouri |
|---|---|---|
| Max speed limit | 70 mph | 75 mph |
| Phone law | Hands-free law | Hands-free law |
| Learner's permit age | Permit at 15 | Permit at 15 |
| Car insurance | 25/50/20 | 25/50/25 |
| Car sales tax | 6.25% | 4.225% |
| Car inspection | Emissions only | Safety + emissions |
| New resident deadline | 30 days | 30 days |
| Helmet law | No helmet law | Under 26 |
| Lane splitting | Not allowed | Not allowed |
Driving laws compared: Illinois vs Missouri
Illinois vs Missouri: Illinois and Missouri match on phone law (Hands-free law) and learner's permit age (Permit at 15).
Max speed limit: Illinois vs Missouri
Illinois is slower on max speed limit, with Illinois with 70 mph and Missouri at 75 mph. Rural interstates reach 70 mph in Illinois and 75 mph in Missouri. Leaving Chicago for Kansas City, verify the posted limit following the border.
Owning a car side by side: the comparison
Illinois vs Missouri: Illinois and Missouri match on new resident deadline: 30 days.
Car insurance: Illinois vs Missouri
Illinois is lower on car insurance, with Illinois with 25/50/20 and Missouri at 25/50/25. Illinois is at-fault and Missouri is at-fault. A policy written in Chicago must be updated following a move to Kansas City.
Car sales tax: Illinois vs Missouri
The rule is higher in Illinois on car sales tax: Illinois at 6.25% and Missouri at 4.225%. For a $30,000 purchase, state tax is roughly $1,875 in Illinois versus $1,268 in Missouri. Buyers from Aurora or St. Louis owe car tax where the car is registered, not the dealer's.
Vehicle inspection and emissions testing: Illinois vs Missouri
The law is stricter in Missouri on car inspection, with Illinois with emissions only and Missouri at safety + emissions. A vehicle based in Aurora is inspected under Illinois laws, even when driven to St. Louis.
Motorcycle: Illinois vs Missouri
Illinois vs Missouri: Missouri and Illinois agree on Not permitted for lane splitting.
Helmet law: Illinois vs Missouri
Missouri is stricter on helmet law, with Illinois with no helmet law and Missouri at under 26. Riders heading from Chicago toward Kansas City must obey Missouri's helmet rule on arrival.
Crossing the line for good
- Illinois vs Missouri: moving from Illinois to Missouri means 30 days for the car registration and 30 days for a license.
- Going from Missouri to Illinois: 30 days for registration and 90 days to switch licenses.
Illinois vs Missouri: questions
Where can you drive faster, Illinois or Missouri?
Missouri (75 mph vs. 70 mph).
Where is the car tax smaller, Illinois or Missouri?
Missouri charges less at the state level (6.25% vs. 4.225%).
Do I need a helmet in both Illinois and Missouri?
Illinois: No helmet law; Missouri: Under 26.