As bad as the driving experience was last weekend on the Waianae Coast, the situation could have been worse: A medical emergency response, or some other critical-response need, could have been delayed by the traffic logjam.

The water main break on Saturday, exacerbated by damage to a sewer line and the subsequent shutdown of part of Farrington Highway for two days, illuminated the public safety risk the community faces. The cause — as it has been for many years — is the lack of a serviceable emergency access road for the coast, when the main arterial highway is disabled.

There is the Waianae Coast Emergency Access Route, a patchwork of public and private roads from Makaha to Nanakuli that opened more than seven years ago at a cost of $5.9 million. Such a makeshift solution, while better than nothing, is less than optimal. But the situation was made worse by the apparent lack of an effective protocol for opening the route to drivers, a weakness that became apparent as the hours passed on Saturday without the necessary diversion of traffic.

Transportation planners at city, state and federal levels must collaborate on a plan for a long-term solution, starting with some immediate fixes. For the future, more permanent alternative routes, such as reinstating emergency access to the trans-Waianae Range Kolekoke Pass road, should be explored. The prospect of the city acquiring at least some of the private sections to eliminate the need for the gates and locks should be considered as well.

More immediately, city and state officials must institute clear protocols for getting the locked and gated segments of the route open quickly, installing signage along the route and educating the public about the alternative route.

This has been a persistent worry for residents who depend on Farrington Highway to get to work, home and school, and simply to live their lives. The highway frequently has been shut down, sometimes both ways, for reasons ranging from car crashes to downed power lines.

The bypass route was intended only as a backstop for public use during such circumstances, and as an alternative path for fire, ambulances and other emergency vehicles.

From the day the route was dedicated, on Dec. 17, 2008, residents were relieved to have at least some fallback when they are stranded during road closures. But many doubted that this would suffice for the long term, and underscored the need for an action plan to put the road into use.

What happened last weekend proved them right. Ironically, the shutdown happened about a week after a town-hall meeting held at Nanaikapono Elementary School to raise this issue, as well as other area concerns, said Patty Kahanamoku-Teruya, a longtime community representative on the Nanakuli Neighborhood Board.

She and state Sen. Maile Shimabukuro, a district lawmaker, agreed that among the many shortcomings is the lack of signage to identify the route. Many people who have lived in the area for years may be able to identify segments of the route but do not know exactly where it is.

Kahanamoku-Teruya makes the persuasive point that Kolekole Pass, which had been opened occasionally for public use before a post-9/11 security crackdown, should be made available in such situations, if military operations at the time do not pose a safety problem.

Shimabukuro acknowledged that condemnation of private roads to make them more accessible would require a major commitment to bring them up to municipal standards and for ongoing maintenance costs. But that investment — as well as forging a connection between Helelua Street and Piliokahi Avenue, at Nanakuli’s southernmost reaches — could bypass more potential bottlenecks and may be worthwhile.

Farrington Highway is a lifeline for the more than 50,000 people of the Waianae Coast.

There needs to be prompt movement toward establishing an efficient, effective emergency alternative.