Question

When drivers feel ___________in a traffic jam, anxiety builds up to escape the confinement of congested traffic?

Answer 1

When drivers feel ___________in a traffic jam, anxiety builds up to escape the confinement of congested traffic?

I'd say maybe
Frustrated 

Answer 2

Despite many feelings could be put in that place, the best options are trapped and frustrated are the best choices.

When drivers feel frustrated in a traffic jam, anxiety builds up to escape the confinement of congested traffic.

or

When drivers feel trapped in a traffic jam, anxiety builds up to escape the confinement of congested traffic.