St. Louis rush hour times
| Day | Morning peak | Evening peak | Worst 30 min | Best time to leave |
|---|---|---|---|---|
| Mon–Thu | 7:00–9:00 a.m. | 4:00–6:00 p.m. | Core of each peak window | Before 7:00 a.m. or after 9:00 a.m.; evening outside 4:00–6:00 p.m. |
| Friday | 7:00–9:00 a.m. | 4:00–6:00 p.m. (often stretches) | Friday evening outbound | Leave earlier than Mon–Thu when you can |
| Weekend | Lighter commute peaks | River-crossing and event surges vary | No fixed weekend commute clock on this page | Outside weekday peaks; delay is concentrated on the Poplar Street Bridge |
When does St. Louis traffic die down?
Morning traffic dies down after about 9:00 a.m.; evening traffic after about 6:00 p.m.; the Poplar Street Bridge decides most bad St. Louis commutes.
St. Louis has a reputation as one of the easier large metros to drive, and it is mostly earned. What it also has is a single structure carrying an improbable share of the region's traffic. Here is what the data says, when the bridge and the loops actually peak, and how to find the best time to leave for your route.
One bridge, three routes, nine lanes
The Poplar Street Bridge carries I-55, I-64 and US-40 simultaneously across nine lanes over the Mississippi. Roughly 100,000 vehicles cross it daily, which makes it the second most heavily used bridge on the river, behind only the I-94 crossing in Minneapolis.
It used to carry more. I-70 ran over it until 2014, when that route was shifted to the Stan Musial Veterans Memorial Bridge upstream — and that realignment is the single biggest thing that has happened to St. Louis traffic in the past decade. Daily volume on the Poplar Street Bridge dropped from about 124,000 vehicles in 2012 to roughly 107,000 by 2014.
That history matters for how you plan. The bridge is no longer at its historic worst, and the Musial bridge gives the region a genuine second interstate crossing it did not have before. But the Poplar Street Bridge still carries three routes on one deck, and when it slows, three different sets of drivers feel it at once.
Nationally, the typical driver lost 49 hours to congestion in 2025, up six hours over 2024. St. Louis sits below that — which is why its bad stretches catch people out.
When is St. Louis traffic worst?
Mornings run roughly 7:00–9:00 a.m. and evenings roughly 4:00–6:00 p.m. By corridor:
- The Poplar Street Bridge — three routes on one deck. The most consequential stretch in the metro, and the one worth checking before you commit.
- I-64 / Highway 40 through Clayton and the central corridor — the main east–west commute, heaviest between downtown and the western suburbs.
- I-70 north and the Musial bridge — now the alternate river crossing, and a real option when the Poplar Street Bridge is blocked.
- I-44 southwest — the commute from Kirkwood and Webster Groves, peaking inbound in the morning.
- I-270, the outer loop — a commute route in its own right rather than only a bypass, because so many employers sit along it.
- I-170, the inner connector — short, heavily used, and quick to back up at both peaks.
Prefer a leave-by time to a set of windows? Put your arrival time into the departure time calculator and it will work out when to go.
The simple move: shift off the peak
Leaving just before or just after the busiest window clears a large share of the delay. St. Louis peaks are narrower than in the largest metros, so the shift needed is usually smaller — fifteen minutes often does what thirty would in Chicago.
A river crossing is the exception. There, the state of the bridge before you leave matters more than the exact minute, because the alternative — rerouting to the Musial bridge or further out — adds miles, not just minutes.
Three St. Louis-specific things that move the peak
- Three routes share one deck. The Poplar Street Bridge is not simply busy; it is busy on behalf of I-55, I-64 and US-40 at once. An incident there is three incidents from the perspective of the drivers affected.
- The 2014 I-70 realignment still shapes habits. Drivers who learned the region before the Musial bridge opened often default to the Poplar Street Bridge out of habit when the newer crossing would serve them better. Worth re-checking your usual route.
- Two rivers, limited crossings. The Mississippi and the Missouri both bound the metro, and crossings are concentrated rather than plentiful. That makes certain commutes structurally exposed in a way an inland route is not.
Why your best time is route-specific
The Poplar Street Bridge does not peak like I-270, an inbound trip is not an outbound one, and a commute that crosses the river is a different category of risk from one that does not. Citywide advice smooths over exactly the differences that decide your drive. Nationally, the worst day of the week varies by city too.
Driving the I-55 corridor north? See the best time to leave Chicago for the other end of that run.
Find the best time to leave for your St. Louis route
Google Maps and Waze show live traffic and turn-by-turn once you are already on the road. BoardSpy is the leave-time app: it checks your saved St. Louis route before you leave, recommends when to go, sends traffic and weather alerts, and tracks delay and on-time stats including your best and worst days. When you set off, it opens your map app for turn-by-turn. For how routing apps differ from departure-timing tools, see best app to avoid traffic and Google Maps commute alternatives.
Just passing through?
This page is for commuters driving in and around St. Louis. If you are crossing the metro on the interstate rather than commuting within it, the timing question is different — see the best time to drive through St. Louis.
Frequently asked questions
When does St. Louis traffic die down?
Morning traffic dies down after about 9:00 a.m.; evening traffic after about 6:00 p.m.; the Poplar Street Bridge decides most bad St. Louis commutes.
What is the best time to leave to avoid traffic in St. Louis?
Generally before 7:00 a.m. or after 9:00 a.m. in the morning, and outside 4:00–6:00 p.m. in the evening. St. Louis peaks are narrower than in the largest metros, so a 15-minute shift often clears what would take 30 elsewhere. If your route crosses the Poplar Street Bridge, check its condition before you commit.
When is St. Louis rush hour?
Roughly 7:00–9:00 a.m. and 4:00–6:00 p.m. on weekdays, with the Poplar Street Bridge approaches and I-64 through the central corridor the heaviest stretches.
Which interstates does the Poplar Street Bridge carry?
I-55, I-64 and US-40, across nine lanes. It also carried I-70 until 2014, when that route moved to the Stan Musial Veterans Memorial Bridge upstream. Around 100,000 vehicles cross daily, making it the second most heavily used bridge on the Mississippi after the I-94 crossing in Minneapolis.
What is the worst road in St. Louis?
The Poplar Street Bridge is the most consequential — three interstate routes on a single deck, with limited alternatives. For day-to-day commuting delay, I-64 through the central corridor and the eastern arc of I-270 are the most consistent.
Is St. Louis traffic actually bad?
Not by national standards. St. Louis sits below the 49-hour US average for hours lost to congestion per driver, and most days are easy. What it has is concentration: a handful of crossings and connectors carrying a disproportionate share, so the difference between a good commute and a bad one here is less about the hour and more about whether your route touches one of them.
How do I find the best time to leave for my St. Louis commute?
Use a leave-time commute app that reads your actual route rather than only a live map. BoardSpy recommends when to leave for your St. Louis route, sends pre-departure traffic and weather alerts, and tracks on-time performance and your best and worst traffic days. Download it here.