I ride at night through the summer and sometimes in the winter but not on the big wide roads that you specify (main roads where I live are lethal). Instead I ride on the same quiet country lanes I frequent in daylight.
Also, as has been said in this thread already, demands on your skill as a cyclist, and on your lamp system, are quite high. My lamp system, which I run in the daytime too as daylight running lights, is described at
http://coolmainpress.com/BICYCLINGbuildingpedelec6.html It lights up the road just like a motorcycle lamp would and is suitable for substantial downhill speed on badly surfaced, narrow but well-known lanes; the lack of side throw in the beam cuts speed considerably on unfamiliar roads. The same lamps are available for hub dynamo operation. Note that, though I loved the first series BUMM Cyo Nearfield lamp, the hotspot means that I cannot recommend the current series Cyo/Fly lamps from BUMM; try the Philips Saferide instead; I refer you to the articles so that you can see the sort of light output you should aim for to ensure reasonable security both in being seen and in seeing, and also in warning off careless or cocky drivers. The BUMM Toplight Line Plus rear lamp shown in the same article is currently the best rear lamp you can buy.
Andre Jute