Hazards 2: Interchanges

I was having a Saturday-morning kaffeeklatsch conversation with some ex-pats from overseas (there are a bunch of them who live out in Maryland suburbia, who work with NASA, in the diplomatic corps, and for agencies, well, let's just say they don't talk about their work very much.) One of them recognized me as a regular cyclist, because he'd seen me often on our neighborhood streets (I was so pleased), and so I gently (honest!) steered the conversation towards cycle-commuting. One of the guys was from Holland, and of course he liked to cycle "back home", but he said the hills in Maryland were too much for him. Another of the guys (an antenna designer for NASA) said that at one time he lived just 9 miles from his work, and (so he said) he would have liked to bike but there was a big highway in the way and he couldn't figure out how to get across it.

I knew the highway he was referring to, and I cross it regularly. There is an overpass about every mile along its length, but the overpasses are secondary roads, legal to cycle on, but certainly intimidating for the inexperienced. The overpasses can be particularly intimidating, and I thought it might be interesting to throw out the method I use to cross them. (Here's a link to the excellent "Infrastructurist" blog that the image at right comes from.)

Let me say right up front that this is vehicular cycling, and I've come to the realization that it's just not for everyone. I think that VC requires a commitment (and, often as not, a little bit of militancy in that commitment) to the concept that bicycles-have-full-vehicular-rights. It also requires concentration, some athletic ability, and some developed cycling skills. With all these ingredients available, VC is not dangerous, but as I say, it's not for everyone. In the America of today, though, it is the way to become carless if you don't want to wait for the powers-that-be to develop infrastructure. (This is not to take anything away from the Urban Repair Squad.)

The skills required for this apparently obvious maneuver are three:

• The ability to ride up a gentle incline (as are most interchanges) and maintain a speed, say, in excess of 10 mph;
  
• The ability to "ride a line" in traffic, to ride right on a highway stripe and not swerve even when cars bypass at speed;
• The ability to look back in both directions without leaving your line of travel;

I say "apparently obvious" because in essence all the cyclist does when crossing an interchange is go in a straight line. I've seen experienced cyclists (although not experienced in the vehicular sense) mess this one up, always trying to be next to the curb or shoulder, and crossing too many vehicular lanes in the process. The State of Maryland "rules of the road" booklet is a little ambiguous on the practice of bicycles and turning lanes. It says:

A bicycle should be operated as close to the right side of the road as practical and safe. However, cyclists are expected to use turn lanes.

It doesn't say, however, in this context how bicyclists are supposed to use them. (I've contacted MD-DOT and will post their clarifications here when and if I receive same.)

So, anyway. Back to the topic at hand, which is the interchange. A most common interchange that one would encounter here in Maryland is the classic "cloverleaf" which I've illustrated in an adjacent image.

I've analyzed the crossing of this interchange and find that it contains seven (!) zones that have to be traversed, and each zone requires a separate response. Each zone is unique, but some are similar to others. Take a look at the illustration.

Our intrepid vehicular cyclist is crossing from bottom to top. The primary road (say an expressway) is the horizontal main road. The secondary road (typically a road with a speed limit of less than 50 mph) is the one our cyclist is on. We'll assume the secondary road has a decent rideable shoulder. (This is not necessary, but most secondary roads of this character do in fact have this, so it's a reasonable assumption.)

So, let's descibe the seven steps of getting across a highway interchange. They are:

1. In this zone the cyclist is riding the shoulder, looking over his left for oncoming traffic that may not see him;
2. In this zone, the cyclist is "riding the line", on high alert for motorists overtaking, not being aware of him, and crossing in front of him from left to right;
3. In this zone, the cyclist gets a brief mental rest (on the shoulder again) and looks to his right to assess oncoming traffic from the loop;
4. In this zone, the cyclist is again "riding the line", on high alert particularly for motorists coming off the primary road overtaking, not being aware of him, and crossing in front of him from right to left. Since there are also cars on the left, this is probably the most intimidating section;
5. Another brief rest. This is similar to zone 3, as the cyclist should be looking right and anticipating;
6. In zone 6, the cyclist will either "ride the line" if there is bypassing traffic on the right, or, if the road right-behind is plenty clear, make an efficient crossing to the shoulder. (I say efficient because for obvious reasons this lane is no place to dally);
7. The last zone, the cyclist has regained the shoulder and is on his way;

So. There you have it, a quite complicated way to get from point A to point B in a straight line. Most experienced vehicular cyclists might well regard this post as both obvious and trivial. But I put it up to make explicit what the requirements are for VC. Mind you, I think the rewards are commensurate, to be sure. Freedom is a wonderful thing.