I was in Copenhagen last weekend and noticed a couple of nice user experience touches in public areas:
These railway ticket machines were covered with plastic sheets to leave no room for confusion as to whether they were in use or not. A common problem I see in London is machines that do not operate, with people going up to them every now and then to check.
This board in Copenhagen airport clearly says how many minutes it is likely to take to clear security. Informed passengers are relaxed passengers, which mean less chance for Airline-type incidents featuring irate passengers.