Whether you're dodging impatient cars after a hard day at the coalface, spinning the pedals on a mid-winter training ride, or caning your favourite singletrack... nocturnal missions on the treadly without making the ultimate sacrifice are a constant challenge.
With only modest application of brain and wallet though, you can significantly increase your visual presence on the road and reduce your chances of becoming a statistic. NZ law requires you to have a red or yellow rear reflector of at least 35sq.cm in area and either yellow reflectors on the front and rear of the pedals (clearly SPD pedals are not standard issue at bureaucracy central) or reflective straps on your lower legs - at any time of the day or night. At night you also need a white or yellow 'steady-Eddie' front light and a steady or flashing red tail light. Both must be visible from at least 100 metres. You can supplement your steady front light with a white or orange flashing number. Slightly draconian to us free spirited velo-warriors but a sensible minimum requirement, although it does over simplify the variables.
On the reflector front... firstly, bigger is not necessarily better. The smaller the pyramid size in the reflector substrate, the better the reflector. So a little reflector with small reflective pyramids can outperform a big sucker with larger pyramids. Secondly, reflectors and reflective clothing (stripes, etc) only bounce light back in the direction of its source. So in urban areas, where vehicles have their lights dipped, reflectors on the bottom half of your body work better than those on the top. And thirdly, movement catches the eye. Your legs move - hence the reflective logos on each calf on the Daddy Long Legs and Jungle Jims.
You'll want a grunty LED flashing tail light to reduce the chances of being collected from behind. The light and battery technology leaps forward in giant Neil Armstrong-like steps. High spec models are as bright as car lights. So if your current light is more than a few years old it maybe time to shout yourself a new, brighter, safer model. The recognised brands offer plenty of options. Ground Effect stocks selected models from Leyzne. USB rechargeable and standard penlight versions all last a long long time between charges. Mount the light high on your seat post. Avoid clipping it to your body or backpack - when you bend forward it's nine tenths useless.
For off-road riding more really is better. As with taillights the technology gets better, and cheaper, each time you blink. Modern LED's coupled with lightweight lithium ion batteries turn night into day. Even basic models throw out in excess of 1000 lumens. Top spec systems deliver over 3000 lumens. The resultant light is comparable to Sebastian Loeb's Citroen and will suitably stun errant marsupials in your path. Mtbr reviews summarises the options from the major brands.
Back on the tarmac, headlight choice is as much about being seen rather than seeing. A USB rechargeable handlebar light (integrated battery - not separate) with around 100 lumens is ample, and reasonably priced. You get around 5 hours burn time and loads of presence amongst the traffic. Ground Effect sells a front and rear commuting combo from Leyzne for around a 100 bucks.
For travelling in traffic, mount your lights on the handlebars so they're at the height motorists expect to see them. With helmet mounted jobs you may be mistaken for a coal miner rather than a cyclist travelling at speed. And while it's tempting to shine them directly into cars so the driver knows you're there, with a high output light you risk the blindingly obvious consequences.
Off-road, helmet mounted lights let you shine them in the direction you're looking, rather than where the bike is pointing. Great for twisty singletrack. However they produce less shadowing than the handle bar versions so it can be more difficult to spot terrain changes and obstacles. If you're limited to a single light then go for the helmet mount. A combination of both is a fabulous money-no-object solution. And will save your bacon if you suffer an electrical melt-down - letting you limp home on one light.
May the force be with you.