I am working in add parking lanes in the highways of Lugo city. For ease the job of locating all the ways that are without the needed tags, I wrote a little Overpass turbo query, after this I load the data it in JOSM to do the tagging.

This is the Overpass query:

[out:xml][timeout:25];

// filter out ways without right or left parking lanes
(
way["highway"]["parking:lane:left"!~".*"]({{bbox}});
way["highway"]["parking:lane:right"!~".*"]({{bbox}});
);

// filter out ways with both parking lanes
( ._; - way["highway"]["parking:lane:both"~".*"]({{bbox}}); );

// filter out other type of ways 
( ._; - way[highway="pedestrian"]({{bbox}}); );
( ._; - way[highway="footway"]({{bbox}}); );
( ._; - way[highway="path"]({{bbox}}); );
( ._; - way[highway="steps"]({{bbox}}); );
( ._; - way[highway="crossing"]({{bbox}}); );
( ._; - way[service="parking_aisle"]({{bbox}}); );

// print results
out meta;
>;
out meta qt;