## Sunday, June 12, 2011

### Golden Gate Bridge: West versus East

Despite swearing off the Golden Gate Bridge last week after a harrowing experience crossing the bridge on the eastern "pedestrian" path, the western path shut down due to "seismic retrofits", I did it again today. Tired from my run yesterday, I needed motivation to ride, and the Mission Cycling ride is a local option to get me out the door.

There were only four of us at the cafe where the ride meets on Sundays at 10 am, and since the hills providing the preferred southern routes were fogged in on this chilly morning, the default took asserted its inertial self and we found our handlebars pointing the way to Marin. One reason group rides are so popular is they relieve one of the burden of thinking.

Arguably the chilly, foggy morning deterred some would-be-bridge crossers, and while the way out was very slow, it wasn't too bad. The way back, however, is where chaos bloomed: by the afternoon the sun had come out and that sent the tourists.

At one point I was following another rider on the right of the path, each of us going walking speed, when I had to slam on the brakes. A tourist had been pressed against the roadside railing shooting a photo of others in her group. Her mission accomplished, she darted back across the path, clearly without looking.

Anyway, I survived, and renewed my vow to avoid the bridge in coming weeks.

I decided to quantify the delay the present state of affairs is causing. Fortunately Strava maintains a database of my bridge crossing times. So Here's the numbers applicable to my rides over the past year that I've used Strava, at least those rides where I've used the GPS and uploaded the data (which is most).

Northbound:
22 rides on western path: avg = 446 seconds, σ = 41 seconds
2 rides on eastern path: avg = 577 seconds, σ = 64 seconds

Southbound:
22 rides on western path: avg = 425 seconds, σ = 36 seconds
2 rides on eastern path: avg = 679 seconds, σ = 13 seconds

So the eastern path has been around 131 seconds slower northbound, 254 seconds slower on the southbound. This is because both of my southbound east-path rides have been in the more crowded afternoon, while my northbound rides have been in the less crowded morning. This is an added delay of 385 seconds = 6 minutes and 25 seconds to the round trip.

It's claimed up to 6000 cyclists per day ride the bridge. If each of these "cyclists" is one-way across the bridge, and each is delayed on average as much as I have been, then that's up to 321 rider-hours per day of delay.

Now 6:25 doesn't seem like a deal-breaker in terms of a decision of where to ride, although since I was late in getting home today I wish I'd had that back. The real cost is in the nerve-racking unpredictability of the tourists: typically walking three abreast, suddenly jumping across the path for photos, even (in one case I saw today) riding a bike while holding a videocamera in one hand, handlebar in his other, two eyes on the view, none where he was going. It's fairly crazy out there.