snarl up
verb1
to entangle
2
To become tangled; to become entangled
3
To block (traffic); to cause (traffic) to be congested.
4
Of traffic to become congested.
5
To put into disarray; contort; confuse; muddle up
snarl-up
nounalso spelled snarl-up1
Australia, New Zealand, UK A traffic jam.