Roads and road signs Lesson 31 of the technology course of Mova's primary school: 18 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: the lesson at school .
0 A road looks like a flat black strip, but it is really a layer cake. 1 At the bottom is hard-rolled crushed stone that spreads the weight of lorries, and on top is asphalt, a hot mix of small stones and sticky black bitumen, rolled flat while it is still warm. 2 Water is a road's worst enemy. 3 On a winter night water seeps into a tiny crack, freezes, swells like a bottle of water left in the freezer and pushes the crack wider; tyres then knock the broken bits out, and a pothole is born. 4 Roads also talk to drivers without words. 5 Shapes and colours on signs, white lines with glittering glass beads, cat's eyes that shine back in the headlights and bumps outside a school all tell a driver what to do in a split second. 6 The safety rule for every road is the same: roadworks and motorways are for vehicles and trained crews, never for walking or playing. 7 A road is built in layers: crushed stone rolled hard at the bottom, then hot asphalt, a mix of stones and sticky black bitumen, spread and rolled flat on top; people often call it tarmac. 8 Potholes grow after winter because water gets into cracks, freezes, expands and breaks the road, and traffic then knocks pieces out; councils fill them, and cyclists watch for them. 9 Road lines are painted with special paint that has tiny glass beads in it, so the lines reflect headlights at night. 10 Cat's eyes, the little reflectors set into the middle of the road, were invented by Percy Shaw in England in 1934. 11 A motorway has no crossings and no traffic lights, only gentle bends, several lanes and slip roads to join and leave; the first UK motorway, the Preston Bypass, opened in 1958. 12 Never walk on a motorway; if a car breaks down, everyone gets out on the side away from the traffic and waits behind the barrier. 13 At a roundabout drivers give way to traffic already coming round, so cars keep moving instead of stopping at lights and only stop when something is coming, not because a timer says so; Swindon's Magic Roundabout is made of five small roundabouts around one big one. 14 Street lights switch on at dusk because a light sensor notices the light fading; many are now LEDs, and some dim late at night to save energy. 16 In the UK and much of Europe, circular signs give orders, triangular signs warn and rectangular signs give information, and a reflective coating makes them shine at night. 17 A gritter lorry spreads salt before a frost, because salty water freezes at a lower temperature than plain water, so ice forms less easily. 18 Temporary traffic lights at roadworks take turns letting one direction of traffic through a single lane, using timers or sensors. ← previous Bridges and skyscrapersnext → Power stations and the grid↑ back to Technology This page in Markdown → https://md.mova.elamur.ai/free/en/corpora/school/technology/31-roads-and-road-signs/