When you see one funeral procession, you are likely to see several more because they choose the days based on several shared factors, the phase of the moon being one. It is a good reminder of the brevity of life and the importance of the eternal destiny of our souls.
On a less spiritual note: behind those hundreds of people walking slowly, are lots of cars and motorbikes trying to find an alternate route. I was one of these motorbike riders that found an alternate route, only to get stuck at another intersection that was clogged up because another procession was passing by. When the funeral pyre carrying the body reaches an intersection, the people carrying it spin the container about 4-5 times. This is believed to confuse the soul and make it difficult for him to return to his home and disturb the people there.

I took this picture really quick while on my bike. The funeral pyre can be seen in the center of the picture between the bus and the white tanker truck. Remember to click on the picture to make it bigger...