Roadcraft - Police Driver's Handbook PDF

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Wr^llicr' felloe biftfSi^?'H^^^l5-. ; i iw^rds In tli9 df ivhg'erw^^^ant.81 The road surface in winter if you decide to drive on. follow the steps below: In winter, the ice or frost covering on road surfaces isn't always uniform. o In a vehicle with a manual gearbox - engage first gear and keep the Isolated patches remain iced up when other parts have thawed out. and engine running at just above idle speed (just enough to prevent stalling). certain slopes are especially susceptible to this. Be on the lookout for ice or In older vehicles, driving at higher revs could prevent water being frost patches, which you can detect by their appearance, by the behaviour drawn into the exhaust system. In many newer vehicles, the air intake of other vehicles and by the sudden absence of tyre noise: tyres travelling on is positioned below the front bumper so avoid higher revs as this would cause water to be sucked into the engine causifig extensive damage, ice make virtually no noise. Adjust your driving early to avoid skidding. o In a vehicle with automatic transmission - refer to the See Chapter ,7 Maintaining vehicle stability. manufacturer's handbook for specific advice as this varies from one automatic system to another. Driving through water Whichever type of vehicle you are driving; Drive through the water at a slow even speed (a slow walking pace). Driving at speed through water can sharply deflect the front wheels and » Grip the steering wheel more tightiy to maintain direction as you drive cause you to lose control. through the wafer. See Chapter.7 page 148. Aquaplaning. * When you leave the water, continue driving slowly and apply the foot Take extra care at night, when it’s difficult to distinguish between a wet brake lightly until the brakes grip. Repeat this again after a short while road surface and flood water. Flood water can gather quickly where the until you’re confident that your brakes are working normally. road dips and at the sides of the road in poorly drained low-lying areas. If just one wheel enters a deep puddle (usually the nearside wheel), that Dips often occur under bridges. wheel v;ill slow rapidly causing the vehicle to veer in that direction. If you Slow down as you approach a flooded area. Avoid driving through water can't avoid the puddle, prepare by tightening your grip on the steering wherever possible. When you have to drive through water, drive through wheel and holding it straight until clear. the shallowest part but look out for hidden obstacles or subsidence, if the road is entirely submerged, stop the vehicle in a safe place and cautiously find out how deep the water is. The depth of water that you can safely drive through depends on how high your vehicle stands off Road signs and markings the ground and where the electrical components, engine, air intake and Road signs and markings warn of approaching hazards and give exhaust pips are positioned. For example, submerging a hot catalytic instructions and information about road use. Use your observation skills to converter could cause damage. read the road and link the signs to the hazards ahead, especially at night. Refer to the manufacturer's handbook for specific advice for your vehicle. » 78 Roadcratt - The Pchce Dftver‘s HancSxxsk St Chapter 4-AnUQpallfKj hazards in Jhedriwngerr/ironfnBnl 7S ^E« Surfacing materials Grip characteristics Problems Tarmac or asphalt Tarmac or aspnalt In time, they ~ surfaces give a good become polished grip when they're and lose dressed with stones or some of their chips. skid-resistant properties. Surfaces that slope dov,»nwards Surfaces that slope upwards Anti-skid surface High-grip anti-skid to the inside of the curve help to the inside of the curve make When newly laid, cornering, surfaces are designed loose gravel on cornering more difficult. to give extra grip on the surface can the approach to fixed reduce grip; See ChapterW, page 180. Camber and superelevation. hazards such as patches can roundabouts, traffic lights become polished The surfaces of most roads are good for road-holding when they’re clean and zebra crossings. overtime. and dry. Snow, frost, ice. rain, oil, moist muddy patches, wet leaves, dny Concrete Concrete road surfaces Some hold water, loose dust or gravel can cause tyres to lose grip, making skids more likely. often have roughened which freezes Rain may produce a slippery road surface, especially after a long dry spell. ribs, which give a good in cold weather At hazards such as roundabouts or junctions, tyre deposits and diesel skid-resistant surface. and creates a spillage may make the surface slippery at exactly the point where effective slippery surface steering, braking and acceleration are needed to negotiate the hazarci safely. that isn't easily seen. Cobbles Low grip when wet. Rain increases Road surface irregularities Brick paving or pavers on roads in home zones the likelihood of skidding. Look out for irregularities, such as potholes, projecting manhole covers, Road paint sunken gullies and bits of debris, which can damage the tyres and suspension. If you can alter your road position in plenty of time to avoid them without endangering other traffic, do so; if not, slow down to reduce shock and maintain stability as you pass over them. Metal hazards on the road Poor grip when dusty Rain increases surface such as tram lines, or wet. the likelihood of temporary metal sheeting, skidding. inspection covers  r r" 76 Roadcraft - The Pchce DfiWs Handbook Chapter 4 - ArTJcipatiryj hazar-is 'n the dri-.'lrig environment Observing when visibility is low When visibility is low, keep to a slow steady pace and use the edge of the carriageway, hazard lines and cat’s eyes as a guide, especially when approaching a road junction or corner. Staring into featureless mist tires the eyes very quickly. Focus instead on what you can see; the vehicle in front, the edge of the road or the road ahead. But avoid fixing your focus on the tail lights of the vehicle in front because they'll tend to draw you towards it and you could collide if the vehicle stops suddenly. Be ready to use your horn to tell other road users you’re there. Always be prepared for a sudden stop in the traffic ahead. Don’t follow closely, and only overtake other traffic when you can see that it’s absolutely safe to do so. This is seldom possible in fog on a two-way road. At junctions when visibility is low, wind down your window and listen for other vehicles, and consider using your horn. Ice and wetness can linger in areas of shadow, Micro climates Look out for evidence of micro climates. These can cause frost and wet Road surface patches to linger in some areas after they’ve disappeared elsewhere. Ice can linger in landscape features such as valley bottoms, shaded hillsides Have you ever failed to spot a problem on the road surface that and shaded slopes, or large areas of shadow cast by trees or buildings, affected your tyre grip or vehicle handling? and result In sudden loss of traction. Bridge surfaces are often colder than the surrounding roads because they’re exposed on all sides, and can be The type and condition of the road surface affects tyre grip and vehicle- icy when their approach roads are not. Patchy fog is particularly dangerous handling characteristics. Driving control depends on tyre grip for steering, and is a common cause of multiple collisions. acceleration and braking. Even the best tyres on a high-performance vehicle can lose traction on a poor road surface. Most drivers don’t pay enough attention to this. Always look well ahead to identify changes in the road surface, and adjust the strength of your braking, acceleration and steering to retain adequate road-holding. Always observe the camber of the road on a curve or bend.  74 Ro.d„«,^TtaPol,ceCta'sH„dtaok '.I ;VJ^rChaptor4-Anlic;patin8,e2ards in the driving environment e toWhen you drive at night, Wnk about how to adapt your driving take account of these factors: 75 -;s:::-:::^'^'~.on,hb,i.e you’re 'leatherconditions conditions, see Chapter 12 on fast-moving roads. driving, The condition of your vehicle, prepared for night driving? Is it properly equipped and Using lights in bad weather Choose observation '"[o^'^ation inandthe environment. How do you adapt your your lights according ,0 the circumstances. ci snticipation when Switch in darkness? you make a journey because sidelights a general rule =.r:r rise your dipped headlights Whenever your wipers are Weather conditions '0 constant use. "hen there's fog or tailing eight, fog lights often better view than - ni give a dipped headlights. Use -nappropriate driving. creLl Ire'r^^aton'^'''^^ (328 feetj or less. Switch off your fog lights other drivers. them if visibility is 100 metres when you leave the fog so in you don’t dazzle Don’t use another In extreme weather conditions, ask vehicle on the fog ahead, -Stoptingthedriv:::r^^"“°'"^ 'eally necessary?’ yourself;‘Is my journey The brightness of Trie weather affects how far you can see e e more distance between^ou^me cT"" T" gently yourself, ®'^d aim to brake so it's central tc your observation anSpar ''°Z “"'’*'"9' weather conditions reduce visibilitv ren "hen Check your actual 30030^^ " ’«9rilariy Using auxiliary to SlopIf It'SWithintoggy,the ,c„g. distance you causae tn h , he able in bad weather controls and instruments Examples of weather condkions that reduce visibility are; Make full use of your washers and wi fog and mist heavy rain rear window as clear put freeze-resistant as possible.-ZTherST’'°“^“'"^=^-" screen wash in the possibility of freezing foo and snow and sleet or snow, regularly check screen wash reservoir in foo rain bright sunshine, especially when it’s low in the sky. visibility distorts yorir PercZL~Cyr' judge speed accurately. ^ your eyes to