On Thu, 17 Sep 2015 11:01:22 +0100, Roland Perry wrote:
Trains could have some system linked to checking if a seat was occupied
(although their are issues if people put bags on seats) and have
coloured lights above indicating (eg) Green for empty, Orange for
empty-but reserved, and nothing for occupied. Or maybe red for occupied
and in the foreseeable future a reservation pending.

TfL have something similar for bus top deck seat occupancy in trial:
http://metro.co.uk/2015/04/09/good-n...-seat-5141564/

Shorter seat backs though.