IPA: /ˈtoʊlˌbɑr/
KK: /ˈtoʊlˌbɑr/
A barrier that is placed on a road or bridge where drivers must pay a fee to pass through.
The driver stopped at the tollbar to pay the fee before continuing on the highway.
The word 'tollbar' is formed from 'toll' (from Old English 'toll', meaning a payment or charge) and 'bar' (from Old English 'bearwe', meaning a barrier or obstruction). A tollbar refers to a barrier that requires a payment to pass through.
Think of a 'payment' ('toll') that you must give at a 'barrier' ('bar') to pass through — that's what a tollbar is.
No commonly confused words.