Most likely a sane default but I would think also strongly circumstantial depending on traffic, current speed and weather/light conditions. As the pinnacle of

Most likely a sane default but I would think also strongly circumstantial depending on traffic, current speed and weather/light conditions. As the pinnacle of the animal kingdom we should be able to come up with smarter solutions. I always liked the story of Andrew Hallidie, the man behind promoting the idea of the San Franciscan Cable Car - he and his main engineer William Eppelsheimer were motivated to find a better solution to what was to a high-degree an animal welfare issue. Street cars in SF during the late 19th century used to be pulled by horses which both was dangerous for them as well as passengers: "I was largely induced to think over the matter from seeing the difficulty and pain the horses experienced in hauling the cars up Jackson Street, from Kearny to Stockton Street, on which street four or five horses were needed for the purpose–the driving being accompanied by the free use of the whip and voice, and occasionally by the horses falling and being dragged down the hill on their sides, by the car loaded with passengers sliding on its track..... .... With the view of obviating these difficulties, and for the purpose of reducing the expense of operating street railways (tram-roads), I devoted all my available time to the careful consideration of the subject, and so far matured my plans that I had California Street (a very steep street in San Francisco) surveyed [between Kearny and Powell streets, a distance of 1,386 feet] in 1870 by an engineer of the name of David R. Smith, and in the Sacramento Record, a newspaper published in the City of Sacramento, California, in 1870, a statement is there published in its telegraphic news of what I proposed to do, viz: to run a rope railway to carry passengers from the city to the plateau above." http://www.sfmuseum.org/bio/hallidie.html http://www.sfmuseum.org/bio/hallidie.html https://en.wikipedia.org/wiki/San_Francisco_cable_car_system https://en.wikipedia.org/wiki/San_Francisco_cable_car_system