Audax without a car

[meic]

Extended Calendar Events.
http://www.aukweb.net/diy/ece/

It is just a way of getting recognition or "points" for your ride to and from a normal Audax event.

[PH]

I doubt I'm unique because many shorter Audaxes don't even get into double-digit participation lately and I suspect start times/locations are part of it.

I'm wondering if Audax being quite a niche activity, the short ones attract, well, only a few brave local souls, while the really big ones attract those few brave souls from a much wider area (even from abroad) and are therefore particularly well attended.

The full list of the 525 rides in the 16/17 season can be found here, along with the number of riders. I always have a look at the previous year before booking, when they're popular it's usually with good reason.
http://www.aukweb.net/results/archive/2017/events/
It's far more likely for an event to fill up and close entries than for there to be single digit riders, though there may be a handful of those. Participation does vary with region, in the midlands the shorter ones attract quite a few roadies who treat it as a training ride. Where longer and shorter rides are offered next to each other, the shorter is likely to be more popular. I see from that list that the last one I did had 30 on the 200 and 54 on the 100. I also notice that the majority of riders on the 200 were AUK members while the majority on the 100 weren't.
People ride them for all sorts of reasons, I'm firmly and proudly at the tourist end of the spectrum, though I also appreciate the physical challenge.

[TrevA]

To echo what PH says, most of the 100k audaxes around my way, sell out by the closing date, with 100 or 120 entries. That's probably because we are in the middle of the country with good transport links. Though most people riding them are local, with each local club having 10 or more riders taking part.