According to one view quoted in the Mechilta on the opening of our parsha, "derech hamidbar Yam Suf" is not just a description of the direction Bnei Yisrael were travelling (as that could have been stated much more succinctly), but is an agenda statement of what needed to be accomplished. Based on various derashos, the Mechilta explains "derech," as a hint to kabbalas haTorah, "midbar" as a hint to the mon eaten during the desert travels, and "Yam Suf" as a hint to splitting of the sea. We see that from the first moments of their journey Bnei Yisrael were guided with a purpose and mission beyond just getting anywhere-but-Egypt.
What amazes me about this Mechilta is the assertion that the mon and kriyas Yam Suf were built into the plan. Had you asked me, I would have said that the mon came about only because Bnei Yisrael had no other food in the midbar; kiryas Yam Suf came about only because the Egyptians foolishly pursued Bnei Yisrael after letting them go. Had dire circumstances not dictated the necessity of Divine intervention, these miracles could have and would have been avoided. Not so says the Mechilta! Bnei Yisrael had to experience mon, so they were led into a midbar where Hashem would provide it. Bnei Yisrael had to experience a kriyas Yam Suf, so Hashem brought them to the banks of Yam Suf with the Egyptian army in hot pursuit. The circumstances did not create the need for the miracles; the need for the miracles to be experienced led to Bnei Yisrael being put in circumstances that would warrant them. (A similar idea that comes to mind is the idea of the Imahos being akaros in order to elicit their tefilos.)
"Vayasev Elokim es ha'am derech hamidbar Yam Suf" -- Noam Elimelech reads "vayasev" as related to the word "sibah", reason. "Vayasaiv Elokim" means Hashem created the reason, the circumstance that caused Bnei Yisrael to enter the midbar, which he takes as representitive of hisbodedus, and Yam Suf, which he takes as representative of the yam of learning.
It's funny when people relate stories of hashgacha pratis -- Hashem saved Ploni from a fire; Hashem saved Plonis from being hit by a runaway train, etc. -- they always seize on the miraculous escape as evidence of Divine intervention, as if the world was running on its merry course until the point the skies opened and Hashem decided to seize the reins. But of course that's not how it works. Hashem creates the circumstances too -- he put the person in the path of the runaway train and did nothing to stop the fire from starting. We often don't understand why those circumstances were created; they may be there just to elicit the tefilah that brings about the ultimate salvation.
If I can take a little poetic license, maybe "vayasev" is related to sovev, to go around. The midbar, the barren-consciousness alluded to by the desert (to come back to the Noam Elimelech) stands in perfect contrast to the Yam, the quenching waters of Torah. Life takes us as a people and as individuals in circles. The route out of Egypt, whatever we are slaves to, is not linear -- we go ups and downs, steps forward and steps back. So long as we are headed in the right direction, that's how it should be.