Bradford council aren't keen on maintaining running tracks, so I set off on a mission to find a flat, paved bit for my intervals today. I found this:
http://farm4.static.flickr.com/3333/3334003026_523...
Unfortunately, while it was long enough, the people who made the cycle track on the top also filled it with a complicated gate every 200 metres. So after running half an hour from home (which is just off the right hand side of that picture), my measured 600m was entirely unhelpful, and I just did 8 x 2.30 (55s) instead. It was undulating but on hard surfaces generally, and then I lost count and did an extra one for fun. Was shattered after 15 mins of warm down and walked up the main road home. Fun times! Not exactly what I'd planned though.