This video was made from film shot during that time period: the earlier 1900's.
What most impressed me about this was the size of these wooden tracks. I always imagined them as short and narrow, just big enough to fit a couple of bikes, but as you can see from the video, they weren't, they were huge. You might think that such a huge track would be enormously expensive, but compared to paving they were really cheap. They did have some problems. They only lasted a couple of years before the weather destroyed them. They were extremely dangerous for the riders because of splinters, not just if they crashed, but even just while riding their machines would kick up splinters. They required constant maintenance, sometimes there were even carpenters working underneath the track to reinforce it as the race was going on up above.
This page has good collection of pictures from the early days.