I was in central london for the first time in ages yesterday and it seems that now all the cycle couriers are using tiny , 12-14inch wide handlebars,
I guess it will allow them to get through small gaps, but rather than srcapping your bars now, wouldnt the fisrt point of contact be your Knees? Ouch!
Knees? Only if you pedal bandy-legged.
When I was (briefly) a messenger in Melbourne, VIC, there was a guy who reckoned his 12" bars let him squeeze between two trams passing in opposite directions. Wouldn't fancy it myself.
Narrow bars have long been a courier thing. They can be helpful - you can always wriggle your body through a gap, but the bars tend to be at wing mirror height.
These days it's part of the fakenger look, like candy-coloured deep V rims and BMX grips. More power to them.
Calmes dans le demi-jour
Que les branches hautes font,
Pénétrons bien notre amour
De ce silence profond.