[Openstreetmap] Tunnels

[Andy Robinson]

How about this for a dead reckoning protocol:

If driving (well preferably as a passenger please!):
1. Log the expired time in seconds to each curve in the tunnel and again the
time at the end of each curve.
2. Note the direction of each curve (left or right).
3. Describe how sharp each curve is on a scale of 1 to 10 (10 being sharpest
and causing severe discomfort at speed and 1 being barely discernable)
4. Log the time when you reach the end of the tunnel.
5. Log the average speed through the tunnel (useful but not vital for a dead
reckoning method)
6. Use your GPS to log the portal points at each end of the tunnel.

For rail/underground tunnels where speed is not available, the time from
portal to portal should be sufficient but would need to remove all the
stoppages at stations :)

Andy Robinson