Friday, March 04, 2011

Conditions on the bikeways, March 3rd

As a followup to my previous post about bikeways in winter, I took some photos of what the conditions are at the beginning of March. There's been a couple of  days with temperatures with daily highs above freezing (as in +1C or +2C when the sun is shining). One can really feel the spring is coming. Wearing the fur hat is unnecessary, water is dripping from the roof, trees are clear of snow and the first birds are singing.

As we know, the cars make ruts on the road, and the ruts are first to clear. The cleared pavement is dark, and absorbs more heat from the sun. So roads are the first ones to be clear of ice. You can estimate how busy the road is based on how soon it's ice free. On this same intersection, the street looks pretty much the same as in November. I have a shot taken in January, and you'll see it's almost completely covered ice.

 Now the ruts are clear again:
A snowy side street

A couple of inches of ice on the sides.
On bikeways, the process is a bit slower. I noticed that I could see the paving in one part of the bikeway, where the maintenance crews had scraped all the snow away, all the way to the paving and the sun got through. This is on a south side of a hill, so it's one of the first places to be snow free.

Once there is ice-free pavement, the sun heats the surface so the melting will spread out fast, if the melt water runs off the bikeway. If it doesn't, the water will freeze during the night and the progress will be much slower.

On the other hand, if you've noticed, there's a lot of trees blocking the sun here. So on bikeways going trough forests, it looks like this:
There will be winter on this bikeway for a while.

These bikeways are about the same as they were in November. The snow banks are higher, but the conditions for cycling are about the same. When the days will get warmer, the top of the ice will melt and then freeze during the night. So the bikeways will be more slippery and full of slush and frozen tyretracks, and the worst biking conditions of the year are ahead.

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