After watching “Ladder 49,” you will never complain about moving to the side of the road to make room for a fire truck. The new movie is the most polished of recruiting films.

Sorry, conscientious citizens, but that doesn’t mean it’s an outstanding movie. Its reverence for the rulebook of movie worship robs it of spontaneity and surprise. Firefighters are terrific people. Firefighters are unsung heroes. Firefighters are ordinary folk. In the post-9-11 world, firefighters deserve our salutes more than ever, but noble sentiments do not necessarily make top-flight movies.

Joaquin Phoenix and John Travolta lead the cast, but the conflagrations are what you’ll remember. They come in a variety pack of towering infernos, warehouse explosions and residential blazes. Under Jay Russell’s direction, the film captures the chaos and horror of fighting fires. The audience becomes keenly aware of the innumerable ways one can be hurt while rescuing strangers and of the near-impossibility of maintaining mental control in the most turbulent of conditions.

Phoenix plays firefighter Jack Morrison, who as the film opens is trapped in a warehouse blaze after a rescue attempt. His reveries reveal his progression from eager rookie to seasoned pro, from loving fiance to occasionally estranged husband. Travolta is his mentor, fire chief Mike Kennedy, who’s married to his job and more a cheerleader than a martinet with his men.

“Ladder 49” represents a crossroads for both actors. Jack Morrison is Phoenix’s first conventional leading-man character, following a successful succession of offbeat roles (“The Village,” “Signs,” “Quills,” “Gladiator,” “To Die For”). For Travolta, the movie marks his further venturing into character parts.

So who ever thought John Travolta would turn into a 21st-century Walter Brennan, specializing in lovable codgers who speak their mind? Actually, Travolta has always been a character actor. Even in his “Saturday Night Fever”-“Grease” reign, his simian features were not those of a traditional movie hero. He’s now at an age where he can fully embrace character roles. But he needs strong screenplays, and “Ladder 49” provides only featherweight possibilities.

Phoenix carries internal angst even into a role as straightforward as firefighter Jack. This conflicted quality happily keeps the character from becoming a top-gun stereotype. Robert Patrick also does a handy job as an occasionally abrasive colleague, the only member of the squad who does not seem to automatically love everyone else.

In fact, the barroom scenes bear down too persistently on the brotherhood that firefighters share. But from any perspective, “Ladder 49” is not a saga told with subtlety.