Origin
O'Fallon, MO
Afternoon in O'Fallon on Thursday
Local time
4:59 PM
CDT
Current temp
57°F
Unavailable
Live forecast
Trip from O'Fallon, MO to Saint Johns, MO
Last recalculated Apr 16, 2026
Drive Time
33m
Distance
22.2 mi
36 km
Drive Score
7/10
Good drive
Same Day?
Yes, doable
Fuel Cost
$3
one way
EV Charging
Unknown
Best Time to Leave
4 AM
0h 30m
★
6 AM
0h 33m
8 AM
0h 39m
10 AM
0h 35m
12 PM
0h 35m
3 PM
0h 35m
5 PM
0h 39m
8 PM
0h 31m
Estimated drive times based on typical traffic patterns. Actual times may vary with weather, construction, and real-time conditions.
O'Fallon, MO
Wikimedia Commons
Saint Johns, MO
Abdel Achkouk
Trip Overview
The drive from O'Fallon, MO to Saint Johns, MO covers 22.2 miles and takes about 33m behind the wheel. This route is realistic as a one-day drive if you keep your stops efficient.
The route leans on I 70, Saint Charles Rock Road, Drennen Parkway for much of the mileage, and the overall profile is highway-focused drive. The longest uninterrupted segment is about 15.3 miles on I 70. At current regular gas prices, budget about $3.47 one way before food or hotel costs.
Who Is This Route For?
Weekend Trip
Doable as a same-day drive at 33m. Total distance: 22.2 miles.
Family Friendly
Moderate complexity with 0 natural rest stops along the way.
Solo Traveler
33m drive, comfortable solo distance.
EV Driver
0 DC fast chargers along the route. Coverage: unknown.
First-Time Driver
Mostly highway driving (73%). Some complex stretches to watch for.
Drive Character
This is a 33m highway drive covering 22.2 miles, with most of the trip on I 70 and Saint Charles Rock Road. The longest continuous stretch is about 15.3 miles on I 70.
Most of the miles stay on highways, which makes pacing and fuel planning easier than turn-by-turn city driving.
There are about 12 navigation steps in the underlying route data, so the final approach matters more than the middle miles.
I 70 is the longest continuous segment at about 15.3 miles.
How Hard Is This Drive?
This is a straightforward highway drive that stays mostly on I 70 and Saint Charles Rock Road. You will hit about 9 points where you need to pay attention to lane position or signs. The trickiest moment comes around 0.6 miles in near Drennen Parkway.
Driving Effort
6/10
Moderate - straightforward overall, but long enough or busy enough to require pacing
Balances navigation complexity with total wheel time.
This drive requires moderate attention. Across 22.2 miles you will encounter 9 spots where lane choice or exit timing matters. Not difficult for experienced highway drivers, but worth previewing the tricky sections before you go.
Where does it get tricky?
The main spots that need attention: at 0.6 miles (Drennen Parkway): Lane positioning matters here; at 1.5 miles: Lane positioning matters here; at 1.6 miles (I 70): Merge point - match speed before joining. Lane positioning matters here.
Critical Maneuvers
5 of 9 key pointsThese are the spots where you need to pay the most attention. Preview them before you drive.
5
0.6 mi into trip
|
~1m in
|
Drennen Parkway
Turn left onto Drennen Parkway
Lane positioning matters here
Use the left lane.
5
1.5 mi into trip
|
~3m in
Take the ramp toward I 70 East: Saint Louis
Lane positioning matters here
Use the slight left lane.
Toward I 70 East: Saint Louis
5
1.6 mi into trip
|
~3m in
|
I 70
Merge onto I 70
Merge point - match speed before joining. Lane positioning matters here
Use the straight / slight right lanes.
7
16.8 mi into trip
|
~22m in
Take the exit toward MO 180: Saint Charles Rock Road
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the slight right lane.
Exit 234
Toward MO 180: Saint Charles Rock Road
5
22.1 mi into trip
|
~32m in
|
Betty Lee Avenue
At end of road, turn left onto Betty Lee Avenue
Navigation decision point
Main Roads
| Road | Distance | Duration |
|---|---|---|
| I 70 | 15.3 mi | 19m |
| Saint Charles Rock Road | 4.5 mi | 7m |
| Drennen Parkway | 0.9 mi | 1m |
| South Main Street | 0.6 mi | 1m |
| Walton Road | 0.5 mi | 1m |
| Betty Lee Avenue | <0.1 mi | <1m |
| Hilleman Avenue | <0.1 mi | <1m |
Longest stretch:
I 70
— 15.3 mi, about 19m
Turn-by-Turn Driving Directions
Step-by-step road directions between O'Fallon, MO and Saint Johns, MO.
1
Start on this road
25 ft
·
7 sec
·
this road
2
Turn left onto South Main Street
0.6 mi
·
1 min
·
South Main Street
3
Turn left onto Drennen Parkway
0.9 mi
·
1 min
·
Drennen Parkway
Use the left lane.
4
Take the ramp
438 ft
·
6 sec
Toward I 70 East: Saint Louis
Use the slight left lane.
5
Merge onto I 70
15 mi
·
19 min
·
I 70
Use the straight / slight right lanes.
6
Take the exit
0.3 mi
·
31 sec
Exit 234
Toward MO 180: Saint Charles Rock Road
Use the slight right lane.
7
Turn right onto MO 180
0.7 mi
·
1 min
·
Saint Charles Rock Road
Use the right lane.
8
Continue on MO 180
3.8 mi
·
6 min
·
Saint Charles Rock Road
Use the left lane.
9
Turn left onto Walton Road
0.5 mi
·
1 min
·
Walton Road
10
At end of road, turn left onto Betty Lee Avenue
457 ft
·
22 sec
·
Betty Lee Avenue
11
Turn right onto Hilleman Avenue
105 ft
·
4 sec
·
Hilleman Avenue
12
Arrive at destination
Hilleman Avenue
Fuel & Cost
Regular Gas
$3.47 one way
$6.94 round trip
$3.97/gal
25.4 MPG avg
8 kg CO2
| Fuel Type | $/gal | One Way | Round Trip |
|---|---|---|---|
| midgrade | $4.36 | $3.81 | $7.62 |
| premium | $4.89 | $4.27 | $8.54 |
| diesel | $5.61 | $4.90 | $9.80 |
No toll roads detected on this route.
Drive Cost (one way)
Fuel
$3
Estimated CO2 emission: 7.8 kg one way. Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $2 in charging · 0 stops · 63% less CO2
| Vehicle Type | kWh | Stops | DC Fast | Home Charge |
|---|---|---|---|---|
| Average EV | 6.7 | 0 | $2.33 | $1.07 |
| Efficient EV | 5.6 | 0 | $1.94 | $0.89 |
| EV Truck/SUV | 8.9 | 0 | $3.11 | $1.42 |
Gas CO2
8 kg
EV CO2
3 kg (63% less)
This trip is well within single-charge range for most EVs. No charging stops needed if you start fully charged.
DC fast charging avg $0.35/kWh. Home charging avg $0.16/kWh. US grid CO2: 0.39 kg/kWh.
Travel Intel
Current conditions at both ends of the drive.
Destination
Saint Johns, MO
Afternoon in Saint Johns on Thursday
Local time
4:59 PM
CDT
Current temp
78°F
Unavailable
Live forecast
Time zone
Same local time
Origin and destination are on the same clock, so arrival timing is easier to judge at a glance.
Temperature spread
21 degrees warmer at arrival
A meaningful temperature swing is a good cue to rethink layers, water, and how soon you want to arrive.
Road read
33m on the road
Use the two city cards together: check the sky where you start, then compare it with the local time and temperature at arrival.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
Frequently Asked Questions
The drive from O'Fallon, MO to Saint Johns, MO covers 22.2 miles and takes about 33m without stops. Add 15-30 minutes for a fuel or rest stop on longer drives.
The main roads are I 70, Saint Charles Rock Road, Drennen Parkway. Most of the drive stays on highways, so watch for ramps and exits.
This is a comfortable same-day trip.
The midpoint is about 11.1 miles from O'Fallon, MO. Look for rest areas, gas stations, or food options near the halfway mark.
At current regular gas prices, expect to spend about $3.47 one way. This estimate uses 25.4 MPG — your actual cost will vary with your vehicle's fuel efficiency and current gas prices.
Leave by 9 AM and you'll arrive before lunch. Even a 4 PM departure gets you there before dark in summer.
This drive requires moderate attention. Across 22.2 miles you will encounter 9 spots where lane choice or exit timing matters. Not difficult for experienced highway drivers, but worth previewing the tricky sections before you go.
The main spots that need attention: at 0.6 miles (Drennen Parkway): Lane positioning matters here; at 1.5 miles: Lane positioning matters here; at 1.6 miles (I 70): Merge point - match speed before joining. Lane positioning matters here.
The route from O'Fallon, MO to Saint Johns, MO does not surface many named destination signs beyond the main corridor.
Yes. Nearby national parks include Gateway Arch National Park.
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