>>Is 60 to old to become an activist?
No, not at all.
And I am sorry about the number of emotions you must have around this death so close to your home.
Is 60 to old to become an activist? It is needed in this area. Where to begin.....
I would look for any sort of local and national cycling organizations and ask them for guidance. Maybe even a local org from another area (like ATA) would give you some tips on getting started. If there are no local organizations fighting for cyclist safety you should start one! :)