Banked roads increase safety because what is increased?
490009
Because the normal force of the road upon the car is not directed straight upwards, as it is on a flat road. The normal force vector is tilted inward toward the center of the radius of curvature (assuming that the road engineers built the darned thing correctly) by an amount equal to the angle of the bank of the road. Decomposing the normal force vector into a horizontal (towards the center of the circle) and a vertical (up towards the sky) shows an increased force upon the car towards the center of the radius of curvature over the case where the road is flat. In the end, it means that the coefficient of static friction that keeps the wheels from sliding radially away from the center of curvature doesn't need to be as high when the road is banked.\n\nAlso note: There is NO SUCH THING AS CENTRIFUGAL FORCE! The car is an accelerating reference frame. Anyone who uses the term "centrifugal force" either has not taken 1st year physics or did not understand it when they did.
65195
because the roads are slippery when wet and some tires don't work well on wet roads,especially worn out ones. \nplus the glares of headlights make it harder for drivers to see the road clearly.
933436
Boy, where to start?\n\nAll except dirt roads have a "base" or "road base" under them consisting of gravel or other mineral soil (not clay or silt).  It serves many purposes - it distributes the load to a wide area of underlying native soil (forces from a point load bear within a 45-degree angle so a 2-foot-thick base spread a load to a 4' x 4' area).  For an interstate, that can be 3 or 4 feet of gravel top by as much as a foot of concrete.\n\nAnd, in freezeing climates, the base separates and therefore protects the pavements from freeze-thaw movement of wet ground beneath.  In extremely cold climates with wet, fine-grained soils beneath, as much as 15 or 20 feet of gravel can be needed.  The Alaskan Highway through northern BC and Yukon is an example.\n\nAsphaltic versus portland-cement concrete (they are both concretes but are often called blacktop/macadam/tarmac versus concrete):  Portland cemernt is a stronger and more versatile binder - for instance, you can use rounded gravels.  Asphaltic concrete requires crushed stone with its angular pieces with greater surface area.  Also, asphaltic concrete is senstive to creep at very high temperatures.\n\nBoth AC and PCC are available in many, many forms.  Strength, temp resistance, salt tolerance, cure times, etc are by selected as needed.  And the aggregate (the gravel inside) is important.  The concrete mix can't be stronger than the aggregate used to make it.\n\nPCC is rarely used without steel reinforcement.  They make a great composite material because the concrete is very strong in compression while the steel is great in tension.  That's why you see workers threading together an intricate cage of steel before pouring a concrete roadbed nad especially before pouring a wall, column or bridge.\n\nThermal expansion/contraction - yes, many roadways are poured with expansion gaps - they cause rhythmic bumps as you drive along.  AC is often poured continuously.  The cracks that naturally form get bigger in the cold when the pavement contracts.\n\nHope that helps a bit.  Engineers spend a few semsters studying concrete design and some people spend their whole careers on it.
432225
a. more current\n more turns would do it too\nMIKE
1129597
People hate the fact that they have to drop money to drive on a road.  The price of gas is high enough already and now you want to add an additional cost to driving?  There are other ways to build road improvement funds.  Many ways.  Government, rather than loves to collect more money in anyway possible.  If the people voted down the tolls, would road repair stop??  NO!  They would find another way to collect for it.
186574
to teach people to drive saftly.
306984
traffic\nloud people\ndisrespect
1068115
What could bring order out out chaos on the roads faster than heavily fining or jailing morons who endanger the lives of others. \n\nOh, I know! Higher insurance rates which also often result from the actions of fool hardy drivers.\n\nI'd double the fines if I was Dictator for a Day to let the stupid people drive themselves to the poorhouse.
308644
the best example for your answer is travel/cargo industry.if coz of heavy rains/earthquakes road&rail system damages, it seriously affects the industry.where the prices of the commodities increase which cargoed by these carriers...consequently economic conditions change....hope that clarifies your q ;)
505282
to keep your roads in repair, to pay pensions, any disaster anywhere or in your own country - relief fund. the police force, army, navy, government salaries, It costs money to run a country, roads dont repair themselves.
960318
Remember that there is friction acting on the car from the movement of the wheels over the road. Work must therefore be done to overcome this friction.
48090
The water on the roads decreases traction for the tires on the cars therefore making it easier to perform stunts that involves skids and sliding around.
683456
I don't know about the rest of the country, but speed traps on highways are very popular where I live.  Some towns finance over half of their annual budgets with speeding tickets to out-of-town drivers.
1015616
Hands-free! It's safer to drive that way.
50699
Roads are the basis of most economies if not all. Transport of goods is easier if roads are good.
535872
You should show how ice expands and can damage roads and concrete... very stiff materials.\nCheck out the links\n\nOh yes and don't forget about wear and tear cars and other vehicles can cause... I am not sure how much time you have for your science fair project... typical road wear studies can last for years.
957832
Older, more erosion and less break off on cliffs etc.