Anyone who's driven a motorbike in Saigon would quickly realize the that overall street layout is a tad bit haphazard and unplanned feeling. Many of the city's main arterials merge and inter-tangle in a way that feels more like vines in a dense jungle or the blood vessels of a body rather than some pre-engineered geometric grand design. In many ways it's a reflection of the culture, which values practical low-cost solutions, and a sort of coexistence with the past.
Despite the seemingly inefficient layout, traffic always seems to move along (especially on a motorbike) versus the the standstill traffic that's common in developed countries with high engineering standards and rule-abiding citizens. Also, despite all of this Google Maps in the city (and the rest of Vietnam) is amazingly accurate and has no real competitors.