We’ve all been there before. You’re coming up to a stoplight, and it’s green. Right at the crucial moment, it turns yellow. You’re stuck in this awkward zone where you’re too far away to make it through before the light turns red at your current speed, but you’re also going so fast that you’d essentially have to recklessly stomp on your brakes to stop in time. What should you do? Should you speed up or slow down?

Technically, running that red light is illegal. If you can safely stop, you definitely want to do so. If you’re already breaking the speed limit and that’s why it’s tough to slow down fast enough, the police would likely argue that you shouldn’t have been speeding to start with.

However, a lot of other factors come into play. For instance, one study discovered that heavy truck drivers tended not to hit the brakes and would just attempt to make it through the yellow light more often. The reason here is that heavy trucks take longer to stop; it may have been impossible to stop in time, or a semi driver may have thought he or she would jackknife and lose control trying to stop quickly. Is it actually less dangerous to keep going?

That study also looked at which lane someone was in on a two-lane road. Interestingly, those on the left are more likely to stop at the light than those on the right, who speed through it.

No matter what you do, it’s a tough choice to make so quickly. If your split-second decision leads to legal charges, you need to know what defense options you have.