Filter every day on the way to work. My journey is 7 miles, 1 of those on a 40mph DC (which could be a 60 but probably isn't due to its location) and the rest on roads with a 30mph limit, ranging from quiet residential streets with barely room for 1 car to pass to a DC with no houses fronting on to it.
I filter to the front of the queue at every set of lights. I'm quite fortunate that traffic levels aren't really that heavy, so on average I'm only filtering 50 yards or so at a time, with the exception of 1 stretch where I filter through about half a mile of queueing traffic. I usually filter while the vehicles are stationary and merge back in once they start to move again.
What do I watch out for? In my daily commute the main danger isn't lane-switching like it would be on the motorway; it's people letting passengers out into the middle of the road. This is particularly prevalent in the few hundred yards leading up to a fairly new secondary school. It seems like many parents drop their kids off and then turn right at the traffic lights a quarter mile further up the road. Since the queue is typically half a mile long these parents think it's appropriate to let their kids out when they're in the right hand lane.
That's clearly much easier for them than letting the kids out at the pavement
then changing lane!
The other major hazard on that same stretch of road is bus drivers letting their passengers out from the right hand lane and pedestrians who don't look before walking off the pavement through the queueing vehicles to cross the road. Why do they always do that in front of large vans so you can't see them coming? So far I have thwarted their attempts to get me to knock them down.
I always thank drivers who move over to let me by. (and it's always the same drivers every morning). Similarly, another group of drivers can be seen repositioning to attempt to block my way. What's that all about? If I commuted by car it'd take far longer, so I'd have to leave the house earlier, so I'd just be another car
in front of them in the queue making their journey take even longer.