According to Google Maps, it's 1,013 kilometers from Benghazi to Tripoli. Bypassing Kaddafi's hometown of Surt by swinging through the desert adds another 100 klicks. Judging from the spectacular see-saw nature of the Desert War of 1940-1943 and the rebels' new friends' air supremacy, things could change rapidly.
On the other hand ...
From the NYT today:
Rebel fighters trying to retake the eastern town of Ajdabiya said they were driven back on Monday by rocket and tank fire from government loyalists still controlling entrances to the city. Dozens of fighters retreated to a checkpoint around 12 miles north of Ajdabiya, and rebels said at least eight others had been killed during the day’s fighting, including four who had been standing in a bloodied pickup truck that the fighters showed to reporters.
There were conflicting reports about whether the allies had attacked loyalist forces in Ajdabiya. While planes had been heard overhead, the rebel fighters said there appeared to have been no attack on the pro-Qaddafi forces holding the entrance to Ajdabiya on the coastal highway leading north to Benghazi. Ajdabiya is a strategically important town that has been much fought over, straddling an important highway junction and acting as a chokepoint for forces trying to advance in either direction.
The retreat from Ajdabiya appeared to have thrown the rebels into deep disarray, with one commander at the checkpoint trying to marshal the opposition forces, using a barely functioning megaphone, but few of the fighters heeding his exhortations.
"Dozens of fighters retreated"? "Dozens" is not a good word in war when discussing your ally. For example, during WWII, there were downsides to having the Soviet Union as America's ally, but at least the word "dozens" didn't come up much. At this point, the rebel army sounds like they'd have trouble with the forces of The Humongous and Wez in Road Warrior.
I realize that this war comes at a busy time of the year for Obama -- March Madness! -- but there are certain basic questions that the President needs to answer, such as "Are we in it to win it?" "What does 'win it' mean?" and "Who's 'we,' anyway?"