northbound

from WordNet (r) 3.0 (2006)

northbound
    adj 1: moving toward the north; "the northbound lane"; "we took
           the north train"; "the northward flow of traffic" [syn:
           {northbound}, {northward}]

from The Collaborative International Dictionary of English v.0.48

northbound \northbound\ adj.
   1. Moving toward the north; as, northbound traffic.

   Syn: northward.
        [WordNet 1.5]

   2. intended to be used by vehicles moving toward the north;
      -- of roads and parts of roads; as, The northbound lane
      was blocked by an overturned tractor-trailer.
      [PJC]