It is shown that a specification in the Event-B language can be represented by an automata-based program as a non-deterministic composition of simple conditional statements, which corresponds to a narrow subclass of automata-based programs. A specification in Event-B is monolithic. To build a specification, there are no other means of composition, except for a refinement that implements an extension of a previously built specification. Comparison of automata-based engineering method and Event-B modeling method is carried out on two example tasks. Previous solutions to the bridge traffic control problem in the Event-B system are complicated. A simpler solution with deductive verification in the Rodin tool is proposed. The effectiveness of the Event-B verification methods is confirmed by finding three non-trivial errors in our solution.