Thus, in {TAIL ~ an uneven grid} of streets, the velocity may vary from block to block in accordance with the length of {HEAD ~ the fastblocks} 
Thus , in { TAIL ~ an uneven grid } of streets , the velocity may vary from block to block in accordance with the length of { HEAD ~ the fastblocks }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD