back on topic with a sensible answer. around glasgow, there's a relatively good and improving network of cycle routes, so it's possible to commute to and from the town centre and minimise the amount of time you share a road with other traffic - summer or winter.
for wet weather and darker nights, make sure you have the right equipment and make sure it works. some people don't follow these top tips, same as some drivers don't check their brakes, tyres, lights, wiper blades and don't abate their speed in winter conditions. this week, there has been a higher than normal spate of motoring accidents across the central belt. driver carelesness probably contributed and there were no doubt many more near misses, just like the daft lassie on the bike.
as luca-t says, if it's excessively wet or icy, don't go out. there's off-road riding for cycling folks who like that sort of gig.
jaggernaut - on a relatively flat road, say Dumbarton Road, i average about 15 - 20 miles/hour with little effort. how would it be safer, for me or the pedestrians, cycling on the pavement?