On Bicycles, and.... what else is there?

I went to a public meeting on the Potrero Streetscaping project . The principal opposition was from those who fear the loss of parking along this busy, dangerous, high-speed road, which was formally the major through-road along the eastern boundary of the city until that function was taken up by highway 101. Here's my letter to my supervisor, Malia Cohen , which I hurriedly dashed off this morning before riding to physical therapy: Supervisor Cohen: I was at the public meeting last night ont he Potrero Avenue streetscaping. The core issue is the priority our transit-first city is going to place on private vehicle parking versus MUNI efficiency and pedestrian and cycling safety. MUNI is bogged down in traffic and pedestrians and cyclists are being picked off on our roadways at an appalling rate. It is thus imperative to the quality of life in the city that this project moves forward. The key requirement is that traffic on Potrero Ave slow down. The median landscaping, by ...

Usually I like to post summaries of my views on ballot measured, etc, before elections. After all, if we just vote in silence then we get just one, barely significant vote, but it is in discussion of the issues that voters have their real power. However, this election I slacked off, and I post this after I already voted and the polls have closed. This was the smallest election I remember, certainly in San Francisco, maybe anywhere. There were no contested races, 4 city ballot measures, and nothing at the state level. Turn-out will be extremely small. Here's how I voted on the ballot measures: Prop A : Yes. This is a restriction against tapping into city employee health care accounts for other purposes. Actually I didn't look at the nitty gritty details, and honestly I'm not sure how effective it will be, but it has a lot of support and seems like a good idea. Prop B : No. A condo development along the waterfront wants an extension of the normal height restrictio...

As I noted, when dealing with GPS problem cases in the Portola Valley Short-Hills version of the 2013 Low-Key Hillclimbs, I couldn't help but notice every one of the cases I grappled with was an Edge 500. This is anectdotal, so I wanted to take a closer look at the problem. The initial plan was to scrape the HTML from the Strava pages with a Perl app, since the API doesn't provide computer type, but when this didn't work out for me since Strava requires user authentication to see this info bit I started thinking about PHP options but finally when I couldn't sleep last night I just went to the pages sequentially and transcribed the computer identifier from the browser. Brute force. Not elegant. I feel so dirty. There were 69 riders @ Portola Valley who each reported the URLs of their Strava records. I then compared these using the root-mean-square average of the distance from the center of the lines the riders triggered the lines (units: meters). The ideal number...

As we head into week 5 of the 2013 Low-Key Hillclimbs, the trend has been unambiguous: despite excellent weather, rider counts are down since last year. The climbs are just as good as ever, although perhaps so far on the challenging side. Still, comparing the same climb year to year the conclusion is the same. And with SRAM leading the way first with compact drivetrains and then with wide-range rear cassettes, riders on "racing bikes" have access to lower gears than ever before, making the steep roads less intimidating. I plot the trend here. 1995-1997 it became more popular and then peaked, dropping off in 1998 when the series took a break. It came back in 2006 and had to rebuild a following almost from scratch. 2006-2010 There's a clear peak 2006-2009 was a period of rapid growth, but then it saturated, with a clear drop-off in 2012 which has accelerated this year. One hit for 2012-2013 has been the "GPS-timed climbs." These have a lower turn-out t...

This is yet another in a series of the Low-Key Hillclimbs Portola Valley Hills multi-climb day. We used GPS to time riders based on when they were interpolated to have crossed a series of "lines" (essentially passing through virtual pylons) in the correct direction. Between certain lines there was a time budget which was designed to be easy to meet, as long as you didn't dally. The lines were designed to be wide enough so all riders who rode the course would be credited with crossing all of the lines, even in the presence of GPS errors. It all worked so well in testing. But in practice, on "game day", the conclusions from testing proved optimistic. First I'll look at time budgets. I had provided a lot of slack in these, and I needed it. There's two major reasons for this. One is that the test riders were mostly solo. On the other hand the "event" riders tended to ride in groups. With group rides the faster riders would wait at the top...

This is another in a series of the Low-Key Hillclimbs Portola Valley Hills meta-climb. It was the second climb where Low-Key used custom timing code to extract rider times from GPS data. But it was by far the most complex, since instead of one climb where time was the difference between the time at the top and bottom, it was a series of 5 climbs where the times from each were added. I did preliminary testing of the Portola Valley Hills course with 6 data sets of riders who had attempted to pre-ride the course. One did the climbs in the incorrect sequence, leaving 5 riders which the scoring code processed. I had no problem with these riders. But it's a big difference between processing 5 data sets and processing 70. Here I'll look at the GPS tracks I recorded for each of the climbs in the Portola Valley Hills. First, the good. Here's plots for the three climbs ending at appropriately named Peak. The plots are x versus y, where x and y are the distance eastward and ...

There were a number of challenges with organizing the Portola Valley Hills Low-Key Hillclimbs . For example, the Edge 500 GPS quality on Joaquin Road. But one of the more interesting was the scoring conundrum represented by a rider who repeated one of the climbs. The scoring code I used here was originally developed for Kennedy Fire Road last year . There we had a long climb with a number of intermediate check-points. To get an overall time I assigned a time to each checkpoint, but overall time was essentially the time crossing the finish minus the time crossing the start. If the rider completed the course multiple times I'd keep track of times between the start and finish and take the shortest one. If a rider recrossed the start line I'd start over. If he crossed the finish line I'd ignore everything until he recrossed the start line. It was easy. For Portola Valley Hills I added in the cocnept of time budgets for time segments between checkpoints. If a rider ...