In order to stream the live races in 1080p HD, please use Chrome, a free web browser from Google.
Download Chrome: https://www.google.com/chrome
Is 1080p HD streaming available in other browsers?
At this time, Chrome is required for 1080p streaming, as it is the only browser that supports the HTML5 video player. This answer will be updated as support is extended to other popular browsers like Safari and Firefox.