Until you try all the rest.
https://en.wikipedia.org/wiki/Traffic_light#British_standard
In addition to the lights mentioned in the Wikipedia article above, there is often a sound played when it's safe to cross, and there's a device at the bottom of the traffic light controls that allows you to feel when it's safe to cross.
http://www.bbc.co.uk/news/blogs-ouch-22706881
Are the systems from other countries much different (better or worse)?
The sounder (aka bleeper) and device (aka tactile) are for visually impaired pedestrians. In Scotland, you can also have a voice telling you the vehicles has a red (e.g. Vehicles heading North on Main Street have been given a red signal).
Systems in other counties have advantages and disadvantages (IMHO), lack of a clear standard compared to background noise. Too complex, so problems in maintenance. However some difference in sounds give a better indication to pedestrians on the start/middle/end of crossing time.
There is also Countdown - http://content.tfl.gov.uk/PCaTS-Note-2-Overview-Presentation...
1) They used a light with basically the same brightness as they were using for the poles on the opposite side of the road and stuck it at head height. Thanks, now that's all I can see at night. Many people with a VI suffer some form of photophobia, so this is not helpful.
2) It completely disregards decades of unconscious habit/muscle memory formation. We are trained pretty much from birth to look across the road for a visual signal while waiting to cross and it's not there anymore because the new signalling method was used as a substitute instead of a complement.
3) The ergonomics of standing looking sideways at a box which blocks your view of the traffic vs standing facing the road being able to scan traffic in both directions and the signal.
4) Since there are no signals on the opposite pole and most complex crossings have no audible signal, there is no longer any way for pedestrians to know that the state of the system has changed or is about to change once they have stepped into the road.
5) With RE to point 3, it is universal that the new boxes are mounted at 90 degrees to the kerb. This means they are facing oncoming traffic (albeit usually on the opposite side of the road). This means they are in driver's eyeline. What happens when a zombie driver sees a light in their eyeline change from red to green? Three times in the last year I have nearly been run down outside my flat due to this particularly stupid human factors error.
6) For extra stupid, newer installs come with a pedestrian detecting PIR sensor mounted on the top of the pole. Not - as one might imagine - to detect a pedestrian and automatically trigger a request but to detect if a pedestrian has pushed the button and then walked away. These are universally either so badly installed or so poorly designed in the first place that the false positive rate is insane. There is no audible or tactile indication that the system has cancelled your request because you're not standing in the particular 30 cm spot its PIR can see.
So the UK gets A for effort but F for implementation.
Edit : rogue punctuation.
They're an abomination on the level of CSS and the iTunes interface.