I've been doing an experiment on my commutes to work over the last week. I normally ride to work on the roadway. But, I recently have temporarily relocated to a location that has one of those horrible bike paths located adjacent to the roadway (only on one side). This path is about 5 ft wide and is separated from the roadway by anywhere from 5 to 20 feet. In addition, it is poorly maintained, with lots of glass, potholes, and big jumps where new neighborhood roads and business entrances have been 'cut' through it. Of course I know to ride on the road instead of this path, but as an experiment I've been riding it last past week. Here's what I have discovered.
First, this thing is incredibly dangerous--I've 'nearly been hit' everyday save one (that is to say that I believe the average, uninformed casual bike rider WOULD LIKELY HAVE BEEN hit). I was of course looking for these and able to avoid them. I ride this path only with a great deal of attentiveness. In particular, I find it VERY necessary to look back over my shoulder for turning vehicles before crossing every neighborhood, business, or church entrance.
Here are the dangers that I've found in approximate order of danger:
(1) When traveling on the path in the opposite direction of travel of the adjacent traffic lane, turning vehicles traveling in my same direction never see me (they are looking at oncoming traffic for a chance to turn and then they accelerate to get across. Even worse, they often get stopped to wait for a chance to turn, and I overtake them while they are waiting--If I then cross the side street (as I have the right of way) they would never see me until they hit me.
(2) Again, when traveling in the opposite direction to the adjacent lane, vehicles entering from side streets don't bother to stop for the path, but proceed up to the roadway to 'see.' In the extreme, drivers turning right onto the roadway approach looking left for an openning in traffic so they can roll through the stop and pull out. I had one guy that I spotted at about 100 ft coming out of a church parking lot. He NEVER looked to the right at all, and never even knew that I had locked up my brake and swerved behind him (he never saw me at all). This situation is also compouneded by trees, bushes, etc. that block vision. In other words, I can 'pop out' into view only 5 or 10 ft from the crossing.
I am NOT talking about drivers that do the obnoxious blocking of the path when they see you coming--this is merely irritating and not really a safety issue, but one of curtesy (or lack thereof).
(3) Basically the same as above, but for when I'm traveling the same direction as the adjacent lane. In this case, drivers are MORE LIKELY to see me, but many still do not. Particularly drivers turning right off the road onto a side street.
(4) Pedestrains, joggers, dogs, holes, glass, etc. Peds are the most dangerous as they walk unpredictably and are apt to 'move over' at any point, particularly when you are approaching from the rear. The ones wearing headphones can't hear your "Passing on your left/right."
From all of this, I draw these conclusions. The most danger comes when riding on the path in the opposite direction of traffic in the adjacent lane (by far the majority of my 'close calls.') Second, drivers for the most part don't have a clue that adjacent path traffic has right of way over entering and leaving (turning) vehicles--at least here in Alabama, the heart of Redneckia.
As for recommendations; first, ride in the roadway not the path (but then we already knew that). Second, if you must ride the path, treat every crossing (side street, drive, parking lot entrance/exit) as either a stop sign or a yield, depending upon your ability to see. Utmost, you must look behind you for vehicles turning off the roadway. Third, look behind you for vehicles turning off the roadway. Fourth, don't assume that the driver entering from a side street, etc. will honor the stop sign. Firth, look behind you again for turning vehicles!