I was away on vacation when I read online that the city put in bike lanes for a couple of blocks of Ninth Street.

After wading through as many of the predictable comments at the end — “I once saw a bike rider run a red light!!!”; “Cars are evil.”; “Watch out Team Spandex, I’m gunnin’ for ya!”; “Cyclists have rights, too!” — as I could, I started questioning how I felt about bike lanes.

There seems to be a bit of controversy around them.

Some cyclists — not to mention some transportation officials — think they’re a tremendous boon, providing a safe haven for little cost.

Others think bike lanes provide a false sense of security and relegate cyclists to second-class-citizen status.

Who knew there’d be a difference of opinion on a cycling matter?

Honestly, I can see both sides.

I tend to use bike lanes when they’re available, but I’m under no delusion a millimeter-thin line is going to protect me from a ton-plus of metal and glass.

And I have to admit I’m a little cheesed to see the bike lane closest to my house frequently is filled with glass and rocks — and a thin layer of road sand from the first snowfall to the first warm-weather rain.

I’m also dismayed to see bike lanes on new-construction roads that abut old-school pavement; frequently they dump cyclists back on narrow, bike-unfriendly roads. One I ride regularly abruptly ends at Sixth Street; cyclists have to leave the lane to trip the street light, blocking traffic from behind despite a designated bike lane. I’ve gotten the stink-eye at that intersection more than any other I regularly ride. Yet if I mind my manners and stay inside my lane, I can never trip the light and legally cross Sixth Street.

And I admit the picture that accompanied the story — with a bike lane painted to the left of a parked car, with a moving vehicle to the left of the lane — gave me the willies. Though I’ve not yet (knock on wood) been doored, I’ve come close on several occasions. I know my path down Ninth would have followed that of the bike lane, but there’s something about the strict delineation that bothers me.

Truth to tell, I always figured bike lanes were more for drivers than riders. They’re not meant so much to keep cyclists safe — getting doored or right-hooked by a right-turning car is an even-more-likely danger — as to keep cyclists in their place. If I’m being a good boy by cycling in my designated lane, I’m less likely to get in the way of cars. I can’t help but think that compartmentalization puts cyclists at greater risk. If a driver sees a cyclist in the bike lane, I think it’s easy to discount the bike, rather than make a conscious effort to be aware of and careful around it. I see it all the time where bike paths cross roads. Drivers see a bike on a bike path and don’t think twice about turning right in front of it; sharing the road, I think, forces the driver to be more cognizant of the cycle and its path.

Whenever talk of bike lanes surfaces, I inevitably think about sharrows. Sharrows always make me titter, if only because the name makes me think of sharting (Google it if you must; I’m not going there, nor will I be responsible for what you find). Sharrows are road markings where bike lanes aren’t practical. Basically, they’re paintings of bikes with arrows pointing where drivers can expect to see bike traffic. They’re designed to force drivers to expect bike traffic and encourage the shared use of roads.

Sharrows are supposed to have most of the benefits of bike lanes at less cost. As a result, they’ve sprung up in San Francisco, New York, Los Angeles and Portland, Ore.

But I don’t ride any of those places, so I’ll ride mostly open-use roads with occasional bike lanes — where they’re not too glass-strewn or willie-inducing to bear.