I have a question regarding reserve time. If I am on 2hr reserve do I just need to report to the airport within 2hrs? Or do I need to be at the plane ready to fly in 2hrs?

I am planning on living in Richmond VA, about 1 hr 45 min drive from DCA. I am realizing with traffic and parking I am cutting it close. Will I have enough time to wait for the call at home and make it to work on time?