Here is some more snowblowing advice from a front mount blower user, if applicable to a pull behind type;
First, never disengage the pto unless, or until, the chute is clear of all snow. Disengaging the pto with a chute full of snow (especially wet heavy snow) is a great way to instantly end up with a plugged chute when you re-engage the pto.
Second, when the job is finished, be sure to run the blower until all snow is cleared from all moving parts. Then move / rotate the chute full range stop to stop to be sure there is not snow that can freeze and block its movement before the next startup.
Second, contrary to what others have said about running the engine speed for the rated pto rpm, With a gravel driveway, Once you get the hang of your equipment's operation (i.e. how slow you can run the engine (pto) without plugging the chute in various snow conditions), you may find your driveway and yard restoration work next spring to be easier if you slow the pto speed and try to not throw and spread the snow (including gravel) quite so far and wide. I have a front blower with an adjustable deflector on the chute, but I also vary engine speed in order to minimize the areas that I need to clean up each spring. Throw it as far as you need to, get the snow out of the way so you don't get snow banks that cause extra drifting, but remember that you may be the one who has to clean up any extra mess in the spring.
Third, When spring comes and it is time to move the gravel back into the driveway. After the box blade, a power rubber paddle broom
does a great job to really clean things up. Works best (easiest) to get it done before the grass starts growing in the spring.