Well, the front brake has ~70% of the stopping power (both on bikes and cars), so while that will work (assuming you don't skid in the back), it won't be the fastest. You can get quite a bit of stopping out of your front brake without going over, you just have to be precise.
You also have to keep in mind road bikes don't have disc brakes so precision is not part of road bike brakes. Those are most likely caliper brakes, which actually lock up fairly quickly when pressure is applied to the brakes.
Modern road bike brakes are plenty powerful enough with adequate modulation.
The real limiting factor on road bikes is traction.
Disc brakes on road bikes might give a distinctive advantage, even with greater weight. Disc brake rims need not have a braking surface and thus can be lighter having less angular momentum.
You've got a lot more ability to shift your weight on a bike than on a car.
The only time my rear wheel has left the ground while braking is when I've tried to do it intentionally. And I've made plenty of hard stops in thousands of miles of riding.
