Maybe.....
Bridge represents direction (since usually open on both ends, as well as distance beneath you).
Police means authority, but maybe in this case represents your own conscience.
The bars maybe represent choice. And the closer you came to terms with conscience, (cops approaching), the closer the bars closed on you, refusing yourself from self-abandonment?

Cops removing you from bridge may be your own self saving self. Placing yourself in room which prevented you from any possible outside influences that may/may not be causing you further confusion...?

Hmmm....no idea, really.

Shangrala