Map lines (5)
(Other definitions for isobars that I've seen before include "Lines linking places of equal barometric pressure" , "Lines of equal atmospheric pressure" , "Map lines of equal pressure" , "Lines on a weather map" , "15 is strong when they are close" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">map lines</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for roads that I've seen before include "Tracks" , "Thoroughfares" , "Ways, routes" , "Area by shore where ships lie at anchor; streets" , "an answer to all clues, initially" .)