Hmm. In Europe, I got on the bike (a mountain bike I put together myself out of the pars of six or seven different bikes) for all journeys less than 200km.
Really miss it, and have gained two stone in my new life as a car owning person...
however, I find bicycle commuting in Doha an impossibility. First of all, I have never ever seen a female cyclist, and suspect there could be a lot of hassle. Secondly, I have seen several times what was left from a cyclist after some bloody landcuiserist wiped the road with him. NOT pretty.
In short, it's OK if you want a hobby and go out of town to ride on weekends, but for just getting around, forget about it. Road safety is abominable, and then again how on earth do you make yourself presentable for the office after cycling there in 53 degrees celsius? : )