It is a comfortable size to ride with a friend and to allow a safe passing distance for motor vehicles. Sure, motorists occasionally get offended that they can't use it as a right-side passing lane for a few seconds, but this is a minor detail.
Seriously, though. Atlanta has an amazing amount of excess capacity on its roads. There are a few bottlenecks or high volume roads, mostly due to disruptions or interruptions in the street network. These disruptions are created by highway or stadium projects that have led to abandoned streets, and by the suburban cul-de-sac mindset that governed the design of many of our post-1930's intown neighborhoods. Just look up an internet map of the Peachtree Road-Collier Road junction, or the Piedmont-Cheshire Bridge-Lavista Road area, or, well, many others... You see, Atlanta started as some intersecting railroad tracks. The streets evolved around them, mostly following a grid system but twisting and turning to follow the rail lines. Around WWII, as the automobile came to dominate, the grid was replaced by a street hierarchy of arterials, collector streets, and looping local streets with only a few connection points in order to reduce through traffic.
Disclaimer: I am not a planner, I just play one at work. If you think any of my statements are incorrect please tell me.
In ensuing years, much of the growth moved far outside of the center city, and the city tried to lure prosperity back by "fixing" its existing layout. This involved widening roads, adding limited access highways, and generally trying to make it easier to drive around. These projects seem to have been implemented somewhat haphazardly, or maybe they just weren't ever finished. Whatever the case, not a lot of people wanted to live here or drive here. And now, when more people are moving back to the city, many of them don't want to drive if they don't have to.
What does this mean for bicyclists? Well, it means that there are extra lanes all over the place. Some roads start out as two lanes, widen to four or five lanes (all in the same travel direction), and later narrow down to three, two, or one lane. That's a lot of room for little ol' me and my bicycle to use. Plenty of room for cars to pass if they need to. My own bicycle lane, 12 feet wide.
No wonder I'm disappointed by the few designated bicycle lanes we have. They rarely meet AASHTO standards (for example, they are too narrow and/or are located in the door zone next to parked cars), are poorly maintained, and may be located in the wrong place relative to right-turn lanes or bus-only lanes. Not to mention the parked cars, signs, and other temporary obstructions. Here is the designated bicycle lane on Ralph David Abernathy Blvd.
Signs in the Bicycle Lane
Overgrown Vegetation in Bicycle Lane
A well designed bicycle lane or cycle track is a wonderful thing. But until Atlanta gets them right, I'll take a general purpose lane, please!