Portland is one of the rare urban centers where people can get around almost as well without a car as with one.

Walkable neighborhoods tied together with a network of trails provide facilities for people to get to work, school or shopping on foot or on a bicycle in safety.

But that doesn’t mean that the city has it all worked out. There are gaps in the system, where sidewalks and bike lanes suddenly disappear, leaving pedestrians and cyclists dangerously exposed. There are also gaps in the behavior of people, both on the street and behind the wheel, who break the rules of the road, creating unnecessary danger.

As a matter of policy, Portland has attempted to find ways to fill the gaps. It has hired a pedestrian and bicycle coordinator, who advises transportation planners and others about better ways for all kinds of traffic to move together. It has also formed a Complete Streets advisory council, to identify the places that need the most work.

Heavily used areas, like the Franklin Street arterial, should have marked bike lanes, sidewalks and signs that clearly tell all users what to expect in a complex intersection.

But none of that would be of value if people don’t follow the rules. That means cars respecting the three-foot legal limit when passing cyclists. It also means bicyclists obeying traffic laws — such as respecting one-way streets and stop lights and signaling their turns.

Everyone in the city has an interest in making this work. Walkers and cyclists reduce congestion, demand for parking and air pollution. Good facilities help people save money and promote healthy living.

But as gas prices climb, more people will leave their cars at home, so it’s important to fill these gaps now.