This (http://top-topics.thefullwiki.org/Transport_simulation_games) web page gives some interesting traffic statistics about Wikipedia page views of various transport/city building simulation games. The top result, perhaps unsurprisingly, is "Transport Tycoon", followed closely by "Railroad Tycoon". Simutrans is 6th on the list of 16, just one beneath SimCity 4: Rush Hour, and above Chris Sawyer's Locomotion and Traffic Giant.
Simutrans-Experimental is listed separately at 14th - above Transport Giant and Rails Across America.
That's very interesting. The Experimental result is rather puzzling, however, since the page now seems to simply redirect to the main Simutrans article: http://en.wikipedia.org/wiki/Simutrans_experimental
Yes, that is rather odd.
Well, this is probably just the count on that wiki. According to statistics from wikipedia, Simutrans was queried 2293 times in september (http://stats.grok.se/en/201109/Simutrans) and OpenTTD 5473 (what seems a realistic relation, given that both project have their own wiki and the OpenTTD section forum is about twice as active).
For now:
No | Name |Wikipedia Views
07 | Simutrans | 307
15 | Simutrans experimental | 44