Saturn drive cycle (code P0410)

Hello.
I'm looking for some advice. I'm new to "talking" over the web, so please forgive me if I'm looking in the wrong place.
The vehicle I'm working with is a 99 Saturn SL 2, 1.9L DOHC automatic with about 190K miles on it. Failed readiness for emissions. After getting a full diagnostic done, replacing the parts found to be faulty, and disconnecting the battery to clear the computer, only a P0410 code is left.
I have a copy of the prescribed OBD-II Drive Cycle for the vehicle, and am currently putting the car through several rounds of it to clear the remaining code, as advised by the local dealer's service dept.

My question is this: How sensitive are the parameters of the drive cycle? For instance, during the portion of the cycle that calls for driving at 55 for 3 minutes, must speed be maintained between 54 and 56, or between 50 and 60, or is 55 a minimum? Is 3 minutes plus or minus 15 seconds OK? If traffic forces me to slow down to 45, or 25, in the middle of the cycle, does that ruin the cycle? Or, during the half-throttle acceleration phase, what if I'm only at 1/4 or 1/3 throttle? When the decel phases call for "no brake", does that include the parking brake?

I'm having a hard time figuring out if I have actually completed successful cycles or not, and could use some advice. Thanks.

It'll sound weird by try doing it late at night with reduced traffic!

They're pretty strict. IF traffic is getting in the way, then can you take it out on a rural road away from the city? If you don't get it just right, it can be tough to reset. Ive been there.

I've never heard of this before, can someone send me a copy of the drive cycle? I am working on a 410 code right now. If I clear the code with a scan tool do I need to go through this exercise at all? What is the purpose of this drive cycle?