No, it would make absolutely no sense for the tower guard to set up a blockade at the end of the bridge, because Gareth Bryne's army has been holding all of the bridge towns since CoT. Bryne would never allow the tower guard to cross the bridge and set up a blockade at the foot of the bridge, as that would be the same as allowing a sneak sortie from the city intended to reconquer the bridge town and get trade running to TV again. Bryne had the bridge towns under control, and this makes no sense at all. It is actually Bryne who would have barricades up in that location. This is from Dominic at the 13th depository:
"[Bryne would have had] sentries watching for any activity at the gates, half a mile away on the other side of the bridges. He also had sentries at posts near the shore to the north and south keeping a close watch on activity in the harbours (that's the sentry posts from which Egwene and Leane took boats in [COT]) . Bryne also had reserve camps between the bridge towns, in case Chubain attempted a sortie to take back a bridge town. His personal tent was in one of those camps, one on the western shore. His outposts and scouts on the eastern shore were the ones facing sneak attacks by the Younglings."
Also, he proposes this: "A more reasonable set up for the final meeting of Rebels and Loyalists would have been to get the Tower Guard to advance in front of the Sitters on the bridge and set up lines not at the gate of Tar Valon (this is completely useless) but on the bridge itself, in sight of Alindaer, to protect the retreat of the Sitters in case something went wrong (they could ride to the barricades and then Travel away). Mind you, a barricade is rather useless. The Aes Sedai didn't really fear being attacked by Bryne's men, and many Sitters have come and gone freely from Alindaer for months to negotiate with the Rebel envoys in tents set up near the foot of the bridge."
Sanderson had pretty big problems overall with the layout of Tar Valon, the surrounding area and the siege. Among other things, he completely changed the layout of the army and AS camps, making Bryne's tactics fairly nonsensical. I, for one, cannot understand how they managed to ship the book with so many errors in this one particular area, yet the reason is likely lack of time for Sanderson to do proper research, and lack of time for Alan and Maria to find and correct them. Still, that they overlooked the bad problems the Tar Valon area had been stuck with, is actually a bit amazing.