Monday, September 5, 2016

Maps lie, LiDAR doesn't

I was recently on a bike adventure that turned even more adventurous than I expected when a Google Maps mapping error led me and my buddy down a trail that devolved into nothing.  The route was supposed to be the Corral Mainline, a major gravel logging road, but what Google mapped in this portion was actually the route of a natural gas pipeline and not a road at all.  But Open Street Map got it right, as displayed in their OSM Cycle layer:



Two lucky factors let us navigate onward without having to painfully backtrack:

  1. Although we were out of mobile network range, my Google Maps app on my phone had cached some Terrain View tiles.  (This is luck, unlike the regular base map layer, you can't intentionally download Terrain layer maps)
  2. In many areas Google's Terrain View derives its images low-resolution topographic maps, but in parts of Oregon and a few other places it uses LiDAR, a high-resolution elevation mapping technique.  The LiDAR image (on the left above) revealed the topography of the real Corral Mainline so we were able to bushwhack up to it and get back on track. 
Even in Oregon LiDAR coverage is spotty: on our ride we also visited the Nehalem Divide Tunnel but LiDAR was not available there and the ordinary topo maps did nothing to reveal the old railroad bed.

Saturday, July 27, 2013

Creative bikeways in France, Luxembourg, and China

Esch-sur-Alzette, Luxembourg – This could be applicable in a lot of places: make room for bikes by putting the parked cars in between the trees in the sidewalk 'furniture zone'.

Near Lijiang, Yunnan, China – Put the bikes on the safe side of the crash barrier.  Duh.  Solar LED street lights a nice touch too.

Guangzhou, China – I don't understand why barriers like these aren't common everywhere.

Paris, France – Cycletrack, bike sharing station, and Parisian cyclists.  This is what you get when you have the space and money to do things right.

Yangshuo, Guangxi, China – Smooth central section for bikes and motorbikes.  Kudos to Portland for their solution to bikes on cobblestones.

Guangzhou, China – Nice big ramp for rolling your bike down the stairs.

Paris, France – What do you do when there's not enough room 'curb-to-curb' for bikes?  Let the bikes ride in the bus lane and park the cars on the sidewalk.  Actually works in Paris where people appear accustomed to negotiating the mix of walking and driving.

Tuesday, January 1, 2013

Technical Links

These are helpful links that took more time to find than they should have.  Linking to them in a public blog improves the likelyhood that someone else will be able to find them via a search engine.