[GraphHopper] adding adaptivity to graphhopper

[Vivek Nallur]

Hi

I'm a researcher working at Trinity College Dublin, and I'm looking at 
the possibility of adding adaptivity to GraphHopper. To elucidate, I'm 
looking at multiple kinds of needs of users:

a) The user desires a route with particular characteristics (least 
polluted, least noisy, etc.)
b) When multiple users all demand a particular route, during a given 
timeframe (say for a music concert), the algorithms try to provide 
slightly different routes to each user, so as to minimize the chance of 
a traffic jam.

For Task (a), I think the key is to add multiple encoders (in the 
routing/util/ directory) all descended from AbstractFlagEncoder, and 
have them responsible for adding different weights to different 
routes/roads. Is this correct? Would different users demanding different 
characteristics screw up any caching that GraphHopper does?

Just wanted to ask the opinion of the list, if they had any 
ideas/suggestions/stuff-already-tried, etc. Obviously, all successful 
implementations will be added back to the graphhopper community.

regs
Vivek