Older freeways built in urban or downtown areas might have unavoidable curves if there was limited right of way or buildings that couldn't be demolished or relocated for whatever reason. It can be quite scary as a driver to be driving at or below posted speed, enter such a curve, and find something on the other end that shouldn't be there that requires a fast response to avoid a nasty accident.
For similar reasons, some of these freeways' exit and entrance ramps end up configured in unusual -- sometimes confusing -- ways as well. It's easy to find one' self about to get on the wrong ramp in such a situation if one isn't paying attention to signage and/or pavement markings.
Not knowing the area or what led up to the event, it remains to be seen how he managed to get on the freeway past the blockade. However, it's understandable that he likely had an "Oh shit!" moment when rounded and the curve and swerved to avoid the vehicles blocking the main lanes only to find pedestrians on the shoulder that he couldn't avoid -- especially when it looks like they moved into his path when they would have otherwise been safe behind their makeshift barrier.