Here Are The Alternate Routes Around Sarah Long Bridge in Portsmouth

The closure is less than ideal, but there are ways around it!

Via Rt. 95

The first option is the most obvious.  Use Rt 95 North via the Market St. on ramp.  Take 95 to exit 1 and back track to the rt. 1 bypass via Dennett Rd.

Via Downtown Portsmouth

This one is a bit trickier because you're at the mercy of downtown traffic.

From Market St. (exit 7) you'll follow it into town and turn a slight left onto Bow St. From there Bow turns into Chapel St.  That ends at State St. near the "Rosa" restaurant.  You'll be forced to take a left on to State St. which runs right into the (new Memorial Bridge and into Kittery.

If it comes down to the two- I recommend the 95 route.  Unless it's a Friday at 5PM, in which case you're screwed either way.