Best time to leave to avoid traffic

Enter when you need to arrive and how long the drive normally takes. This works out your leave-by time and shows whether it lands inside your city's rush hour.

How the calculation works

Your leave-by time is your arrival time minus the drive. If you enter minutes for getting ready and parking, the tool subtracts those as well and shows when to start preparing. The part most people get wrong is the second step: checking whether that drive sits inside the peak. A thirty-minute route at noon is not a thirty-minute route at eight in the morning, so a leave-by time calculated from an off-peak estimate runs late by design.

After it has a leave-by and arrival pair, the calculator compares that interval with the city's morning or evening rush window — the same windows published on BoardSpy's city guides. A forty-five-minute shoulder on either side of the window counts as the edge of the peak: you are outside the published rush, but traffic is still building or clearing. When your drive hits the peak or that shoulder, the tool offers two alternatives: leave early enough to be off the road before the window builds, or leave after it has cleared.

This tool uses each city's published rush-hour windows rather than a live traffic lookup, which means it works before you set off and without a connection. It tells you when the congestion starts and stops. It cannot tell you about a crash on your specific route this morning, a lane closure, or a storm that stretches the peak past its usual end.

What an example result looks like

Take a Chicago morning commute: you need to arrive by 9:00 a.m., the drive normally takes 30 minutes, and you want 15 minutes to get ready. The leave-by time is 8:30 a.m.; you should start getting ready at 8:15 a.m. Chicago's morning rush runs about 7:00 a.m. to 9:00 a.m., so that drive sits inside the peak — you are on the road for part of the window, and the drive will take longer than the 30 minutes you entered.

The tool then suggests leaving by 5:45 a.m. to clear the road before the peak builds, or leaving at 9:15 a.m. and letting the rush clear first. Those alternatives come from the same rule every city uses: subtract the drive from the start of the window (minus the forty-five-minute shoulder) for the early option, and leave a quarter-hour after the window ends for the late option. Change the city, the arrival time, or the drive length and the leave-by clock and the alternatives move with them.

Cities covered

The calculator includes published rush windows for these metros. Each link opens that city's BoardSpy guide. If your metro is not listed, choose “Most US cities” for a typical 7:00–9:30 a.m. and 4:00–6:30 p.m. pattern, or read the national rush-hour guide.

• Atlanta
• Austin
• Baltimore
• Boston
• Charlotte
• Chicago
• Dallas
• Washington DC
• Denver
• Honolulu
• Houston
• Los Angeles
• Miami
• Nashville
• New York City
• Orlando
• Philadelphia
• Phoenix
• Pittsburgh
• Portland
• San Francisco
• Seattle
• Stamford
• Tampa

Pick your city in the form above, enter when you need to arrive, and the leave-by clock updates against that city's windows. For a live check on a saved route — including crashes and weather — use the BoardSpy app on iOS or Android.

Common questions

How much earlier should I leave to beat rush hour?

Enough to be off the road before the peak window opens, not fifteen minutes before your usual time. In most metros the peak builds over roughly forty-five minutes, so a departure that clears the start of the window by half an hour behaves very differently from one that clears it by five minutes.

Is it better to leave before rush hour or after it?

Before, in the morning, for most people — the morning peak builds faster than it clears. In the evening the reverse is often true, because the tail of the peak thins out more gradually than it arrives.

Does the day of the week change my leave-by time?

Yes. Friday afternoon peaks start earlier and last longer than other weekdays in most US metros, and Monday mornings carry a heavier load than midweek. If you are hybrid, which day you drive is as big a lever as what time you leave.

Do I need to sign up?

No. This runs entirely in your browser and nothing is sent anywhere.