MileCheckMissouri names its back roads with letters, runs two of the country's busiest crossroads interstates, and announces every closure by milepost. Here's how it all works, and how to see your exact mile marker plus live MoDOT conditions in real time.
How Missouri numbers its highways — and letters them
Missouri's mile markers count up from the west and the south: on I-70 the numbers start near Kansas City and climb east to St. Louis. But Missouri's real signature is the lettered route. The state's supplemental routes aren't numbered at all — they're letters: Route M, Route AA, Route ZZ. No other state does this. Those lettered two-lanes carry a huge share of rural Missouri's traffic, and when something happens on one, "Route DD" plus a location is how it gets reported. Mile marker data for every Missouri highway is bundled into MileCheck and works offline.
The corridors people actually drive
- I-70 crosses about 250 miles from St. Louis through Columbia to Kansas City — one of the oldest interstate stretches in the country and a nonstop truck corridor.
- I-44 runs southwest out of St. Louis through Springfield toward Oklahoma, following the path of old Route 66.
- I-55 follows the Mississippi south from St. Louis; I-29 and I-35 fan out of Kansas City to the north.
- US-63 and US-65 run the north–south spines through the middle of the state and the Ozarks.
Where mile markers matter most: the I-70 grind
I-70 between St. Louis and Kansas City is two lanes each way for long stretches, heavy with trucks, and famous for work zones. When MoDOT posts a lane closure or a crash, it comes tied to a milepost — and with 250 miles of nearly identical farmland out the window, the milepost is often the only landmark you have. Knowing yours tells you instantly whether the backup ahead is your problem or someone else's.
Ice storms and Ozark weather
Missouri winters lean toward ice more than snow, and freezing rain can glaze I-70 and I-44 end to end in an afternoon. When it does, MoDOT reports conditions and closures by mile range, and the lettered routes through the Ozarks get slick long before the interstates do. Spring brings its own trouble — flash flooding closes low-lying routes fast, and those closures come by milepost too.
Live MoDOT alerts, in one place
MileCheck pulls live road alerts straight from MoDOT: closures, work zones, delays, and weather conditions, tied to the mile marker and direction so you can see what's ahead of you on your route. The alert and your own position sit on the same screen.
Everyday and emergency
Whether you're grinding I-70 through a work zone, running Route 66 nostalgia on I-44, or broken down on a lettered route ten miles from the nearest town, the mile marker is the location Missouri's roads run on. MileCheck shows yours in real time, down to a tenth of a mile, even where the cell signal drops — and it works on CarPlay and Android Auto.
Keep reading
Nearby state guides: Arkansas · Illinois · Iowa · Kansas · Kentucky · Nebraska · Oklahoma · Tennessee
Missouri drawbridges: every movable bridge, its opening rules →
Essentials: What to tell 911 on the highway · How to find your mile marker · Browse the live mile marker map · All 50 states