From Part 1 of Rails: Building a single-page Backbone app without sacrificing Turbolinks. https://medium.com/p/3e22841cf834

backbone_turbolinks.coffee

window.MyApp =
  Models: {}
  Collections: {}
  Views: {}
  Routers: {}

  initialize: ->
    new MyApp.Routers.Items()
    Backbone.history.start()

shouldLoadApp = -> $('#items').size() > 0

$(document).on 'page:before-change', ->
  if Backbone.History.started and Turbolinks?.supported
    locHref = window.location.href
    title = window.title
    window.history.replaceState {turbolinks: true, url: locHref}, title, locHref

$(document).on 'page:change', ->
  MyApp.initialize() if shouldLoadApp()