Filtering between lanes
Between lanes, monitor your speed and the speed difference to traffic. Before entering, know where you will finish and where you can move if the gap closes.
Speed difference
Compare your speed with both lanes. If one lane is moving at 30 km/h, the other is stopped, and you are riding at 40 km/h, the differences are 10 and 40 km/h. Passing alongside the moving lane feels slow, even though you are passing the stationary cars much faster.
Road speed matters too
With a difference of +20 km/h, you are traveling at 40 km/h when traffic is moving at 20, but at 120 km/h when it is moving at 100. Your speed difference relative to the cars is the same, but in the second case the motorcycle travels three times as far during the same reaction time.
At around 60 km/h or above, keep the pass short
At this speed, it is better not to enter a long stretch between lanes. Limit yourself to a short pass of a few cars, and only when you can already see clear road ahead or a place to merge back in calmly.
Do not go far without somewhere to rejoin
When dense traffic stretches ahead with nowhere to merge, you cannot quickly leave the gap between lanes at high speed. Any narrowing or movement by a car will demand an almost immediate response.
The gap changes width in a corner
Cars follow different radii through a corner. Their bodies and mirrors move relative to one another, changing the width of the passage between lanes.
Between lanes in a corner: only at low speed
Riding between lanes in a corner makes sense only when all the traffic is moving slowly and the passage is wide and clearly visible. A practical example is traffic at about 30 km/h and the motorcycle at about 50 km/h.
At high speed, leave room to lean
At highway speed, it is better to take a corner where there is enough space around the motorcycle to lean and make small changes to your line.
Before the curve
Reduce your speed difference early and check where you will finish the pass. The distance between the lanes may change within the corner.
Decide where to finish before entering
At high speed, do not enter the gap between lanes when a solid stream of traffic extends ahead and you cannot see a place to rejoin smoothly.
Do not linger alongside
Complete the pass and continue, or move into a clear space in the lane. While you remain beside a car, you have little maneuvering room if it moves suddenly.
When the passage starts closing
Reduce the speed difference early and merge where there is enough room to enter the lane smoothly. Do not wait until the gap disappears entirely.
Speed when rejoining a lane
Before rejoining, reduce the difference between your speed and that of the cars around the chosen gap. When you are moving at roughly the same speed, it is easier to merge smoothly between them.