Ken Finch
1) Candi makes a good point. Always neutralizing to one side or the other has never worked since the peloton snakes from left to right depending on the direction of the turns. I think the over taking group should always determine to which side they pass.
2) A 500 meter gap between groups before attacking is a bit much. That's well over a quarter mile. That would be very hard to enforce. I think the gap should be big enough to ensure that there is no interaction between the groups and leave it at that. For instance, no attacking into the back of the faster group that just passed you.
One thing that I think needs to be addressed is attacking out of a group that is about to be passed. Some wiley people in the slower groups time their attacks just before they know the group will be neutralized. Or it happens inadvertently, as happened with me a couple weeks ago. I was in a group of 3 who had attacked off the front and had approx a 100 meter gap when the main group got neutralized. After the race it was apparent that they expected us to sit up as well, even though we were well up the course. In my opinion if you've got that big a gap, you're a seperate group and shouldn't have to neutralize with the rest of the pack. But, what should that gap be?
Having set distances for these things will always be hard to enforce though, as estimating distances while racing will always be subjective. I like performance measurments such as "no interaction" or "no effect" much better then "100 meters" or "500 meters".