Why is an article "the" used before "road"? Is it ok to say "on a road" here?

Native speaker’s answer
Rebecca
No, I don't recommend using "on a road" in this scenario. The phrase "on the road" refers to the act of driving, not necessarily the road itself or a specific road. If we want to say what street we are on, we say the road name, not "on a road." Ex: We are on the road now. We should be there in about an hour. Ex: He's been on the road for 3 hours now. Ex: A: Where ya at? B: I'm on 6th Street. Ex: She'll be on I90 for the next 45 miles.