سر في خط مستقيم إلى
or
إذهب مباشرة إلى

I'm not so sure about this (see confidence level), but Google searches for "make/made/makes a B-Line for" seem to indicate that it means "walk a straight line to" or "take a shortcut to". I don't know if I would choose to write سر في خط مستقيم إلى if I had more context and knew what Bourbon street was all about and why the writer was recommending that a B-line be made to it (because it's worth visiting? because the surrounding streets are too dangerous to walk in?).
If you're not too convinced with my answer or any other answer you receive, it may be worth posting the question on the "English" page on Kudoz.

Check the following sites:

Jim Stangier did not make a B-Line for the official opening of the Millennium SkyTrain line over the long weekend. Instead, he chose to attend the Air ...
www.thenownews.com/issues02/091202/news/091202nn6.html

Once you begin to approach the entrance to the Vault you need to just make a b-line for it. Its surrounded by a bunch of a nastiness. ...
www.aclore.com/hol/pilgrimfiles/atlansparkingstone.htm

that they currently face and look at ways to improve their productivity, not make a B-line for their wallets to improve a one-off quarterly performance. ...
www.laiserin.com/features/issue16/feature03.php

... I guess I would make a b-line for the nearest inhabited planet, one where only warrior males live because their women have all died. ...
www.theromancestudio.com/who10.php

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Note added at 35 mins (2005-04-01 08:32:12 GMT)
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The expression probably comes from the fact that the letter \"B\" is composed of a straight line (|) and two curves. Since the shortest distance between two points is a straight line, then you should \"make a B line\" rather than \"the B curves\" if you want to get somewhere quick.

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Note added at 2 hrs 38 mins (2005-04-01 10:34:50 GMT)
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Thanks to Imane and Mosbadr: The correct expression is \"beeline\", and means, as Imane quotes from Merriam-Webster\'s: a straight direct course (due to the belief that nectar-laden bees return to their hives in a direct line). So my translation was correct, but my attempt at an interpretation wasn\'t!