Not really. Let's say your commute is 50 minutes, with 45 minutes of it being stuck in traffic - during which time you do move, just slowly and unpredictably. During those other 5 minutes though, you might be moving at a pretty good 60mph clip - so that's five miles. Walking that would take an hour.
And that's assuming you're in a walkable place. Many cities aren't built for it, and walking 30 minutes in 102 degree heat in Texas isn't a good option.