This　paper　presents　a　routability-driven　track　assignment　algorithm　(RDTA)　to　efficiently　estimate　routability.　Routability　has　become　a　very　challenging　issue　in　modern　IC　design　and　it　can　be　effectively　estimated　by　routing　congestion.　Track　assignment　is　a　stage　towards　bridging　the　gap　between　global　routing　and　detailed　routing.　And　track　assignment　can　also　analyze　routing　congestion　more　accurate　than　other　routing　stages　like　global　routing.　Some　works　have　used　track　assignment　to　estimate　routability.　In　this　work,　wire　segments　extracted　from　a　global　routing　solution　are　assigned　to　proper　tracks　considering　local　nets,　via　locations　and　pin　access.　The　overlap　between　wire　segments　extracted　from　a　global　routing　solution　can　be　effectively　reduced　by　the　algorithm　so　that　the　solution　of　RDTA　can　effectively　estimate　the　routability.