See the truck in the far distance? Lately, both cars and trucks have been ignoring the ban forbidding them to drive along the canal during the construction. The police used to enforce the regulation but lately, the have been quite lax. As a result, there are more traffic congestions in areas, such as this, where part of the road is blocked off for construction along the canal. Normally, the cause is just one car, or truck, blocking the only available lane.
In the image below, the riders actually lost their tempers. Something you do not see in Saigon very often.
(It took me about 10 minutes to get past this truck)