Comment by Lio

Comment by Lio 20 hours ago

2 replies

> Tell that to cyclists used to navigating mandatory bike infrastructure full of terribly broken up surface.

We’ve had paved, off-road bike lanes where I live since the 80s.

They’re not mandatory but they are highly used and to my knowledge have required almost no maintenance in all that time.

There’s no scaring or resurfacing visible.

The wear and tear on tarmac is directly related to the weight of the vehicles that use it.

The benefits of bike lanes are massive compared to the cost.

MereInterest 18 hours ago

> The wear and tear on tarmac is directly related to the weight of the vehicles that use it.

From empirical studies, damage to the road is proportional to the fourth power of axle weight. A bike with rider may weigh 200 pounds, where a passenger car weighs around 4000 pounds. That 20x difference in weight results in a 80,000x difference in damage to the road.

(That’s not even getting into semi trucks, which are around 40 tons fully loaded. Split along 5 axles rather than 2, that’s 9x the axle load of a passenger car, leading to 6,500x the damage to the road relative to a passenger car, or 520 million times that of a bike.)

[0] https://en.wikipedia.org/wiki/Fourth_power_law

  • usrusr 33 minutes ago

    Yeah, and that model is just wrong unless wear from axle weight is the dominant lifetime limiter. There are many other lifetime limiters (like tree roots pushing up from below), and when road engineers plug in bicycle axle weight into their usual formulas you get designs that barley last a season - even when they aren't used at all.