Have you ever scraped your knee through normal pants in a bicycle crash? Consider what'd happen at 5x-10x the speed. Up to you.

On the very rare occasion I've worn regular pants after my squid summer, I've worn Icon Street Armor knee pads over top. For the most part, I wear riding pants and they're fine for regular use as pants (will detail experience below). I do have nylon sedici overpants, but I find them too cumbersome for regular use - a bit bulky, quite slippery, annoying to slip over boots, and unflattering. I have to be going directly to some shorts event to use them. Otherwise, it's way simpler to shove shorts and shoes in a cargo net and be on my way, changing at the destination.

My favorite jeans are Rev'it with interwoven aramid (no liner). They have thin, flexible, siliconeknee and hip pads that are somehow still CE2. I usually go for a relaxed fit (read: I have thick legs), which they offer in the Philly men's model. They're not much heavier than jeans and the pads are comfortable.

For half the price, I also have Street and Steel aramid-lined jeans and aramid-lined/ spandex-sleeved cargo pants. They're comfortable, though thick. I removed the knee pads due to being a harder foam that never quite sits right on my knee and is annoying to walk with. This is where the Icon knee pads come into play. There is some other S&S jeans with interwoven aramid, no liner, but I haven't tried them.

All that being said, the only pants that have seen pavement are the sedici overpants. A 20mph lowside. I landed on my elbow (jacket had pad) and thigh. It was enough to rip up the pants and add a pair of thumb holes, but I had nothing happen to me besides a tiny rugburn on my elbow from the pad. My regular pants inside were protected. I've had worse injuries from slower bicycle crashes.