[topmonk]

Because with enough honking, they can get the crowd to ignore the traffic light and start to inch forward anyway.

[jgtrosh]

If the lights start spending 2x longer often, surely that will push people to defy the light itself more than they did before.

Using group punishment to curb individual behaviour is always at risk of undermining group obedience.

I wonder what variables affect most whether the policy will be successful or detrimental.

[lopmotr]

If they're already so frustrated, some powerful force must be preventing them running red lights. That force is obviously very strong so it probably works on double-frustration pushiness too.