Lane-splitting ain't that bad. I use car mirrors and bus sides as support. I can lean against them at traffic lights without putting my feet down. Or, I can use them to prop me up at speed if I hit a bump. A foot against a bus goes a long way toward helping you maintain balance after a particularly vicious pothole.
I've smashed car mirrors and truck mirrors before with my bike mirror. Car mirrors really go "POP", followed by a tinkling of shattered glass. The car mirror was the worst for wear. My mirror is simply a USD 8 replacement; it's all plastic mirror & stalk. The damage to the car mirror seemed much more extensive. Keep riding. Cover your license place. Don't look back.
The key to lane-splitting is to whizz past the cars as quick as possible, heaving your handlebars right and left to avoid over-extended car mirrors. Think of "Star Wars" or "Tron".
Motorcycle traffic in Seoul is extremely fluid, though, and perhaps that has affected my outlook on city bike riding. Most motorbikes are 125cc and the rest are 90cc or 110cc Honda Cub copies. There's also the odd 400cc Honda Super Four.
Bikes are accepted-- if not technically allowed-- on sidewalks, on pedestrian walkways, across pedestrian overpasses, on bicycle paths, in the middle of intersections, between lanes, between oncoming lanes, in the bus lane, going perpendicular across traffic lanes and just about anywhere else. For example, I park my bike on the sidewalk, in front of my busy downtown office tower, next to a newspaper kiosk, under a birch tree. Much nicer than those nasty underground parking lots.
I've not yet seen an accident due to lane-splitting (barring my mirror smash experience). Most motorcycle accidents I've seen have been due to the bike rider slipping. Then, secondly, due to a car not seeing the bike zooming toward it, and pulling into traffic.
All in all, lane-splitting's harmless. The keys are rider training, safety armour, reflective vests and tall bright orange flags. With those key requirements in place, lane-splitting at 60kph or 90kph is just a quick way to get to work.
Vroom, vroo~ooom!
-gceaves
Hyosung GV250
Seoul, Korea