IIRC Harbour Traffic ended as a standalone mod sometime back. You should be able to find the last version on terrapins site -
http://u-boot.realsimulation.com/
However, in the supermods GWX or NYGM the harbour traffic mod has been incorporated and improved upon.
Really, don't let some of the reports for GWX put you off. Many people couldn't get used to the change in gameplay/realism when it was first released. You wouldn't believe how many threads where started saying 'GWX is too hard' or the 'GWX Uber Escorts keep killing me'. Do you see many of those now?
You just have to change the way you play. Read the GWX manual (click on my Sig).
GWX is not 'play this way or die' you can still adjust your realism settings and achieve an easier sim.
At the very least, you should fire it up to see what you might miss out on.
