Transport can be a problem halfway up a mountain. Before the industrial revolution, you walked. Or if wealthy enough, you owned a horse. If a farmer, you might have a horse and cart. It was normal to walk three or four miles to work in the slate quarries, and three or four miles back. The advent of the railways increased the possibilities in some locations.
Most of the roads in this area were created in the nineteenth century; a few routes would have been developed from packhorse trails (see my article on Fachwen history). Then more to allow slate to be taken to the sea in Caernarfon, Port Dinorwic (now Y Felinheli), or Penrhyn Quay in Bangor. By present standards they are single track with no centre white line. Villages like Deiniolen or Llanberis have pavements for pedestrians, but Dinorwig does not. The most modern development resulted from the building of Dinorwig Power Station in 1974, which necessitated an extensive modernization of the main access roads to accommodate heavy goods vehicles.
The introduction of the internal combustion engine led to lorries, cars and buses, but as vehicles get larger the roads, with a few exceptions, do not. Unlike the Scottish highlands, few specific passing places were created, so meeting another vehicle on a single track lane requires negotiation. A few years ago an oncoming car refused to back down, which would have been good manners in the circumstances, forcing me to reverse some distance up a steep narrow lane, resulting in my clutch burning out and the most expensive repair bill I have ever had. You are also sharing the road with pedestrians, cyclists, horses and inevitably on occasion in Wales sheep, so you need to be alert.
There are bus services in the area, which have a chequered history. Three local companies have gone bankrupt, and in two there has been fraud on claiming payments for bus passes extensive enough to result in substantial prison sentences. Despite public support services here are hanging by a thread, and their future is uncertain.
There are of course taxi firms, but even these are diminishing as demand goes down, and those that survive outside towns like Caernarfon and Bangor are increasingly dependent on the tourist trade. Being able to drive a car, or have the use of one in the household, is increasingly a necessity. You have to be fit and healthy to use a bicycle hereabouts, although the advent of electric cycles will open up another option for some.