2015

2345 Grand Boulevard, Suite 700 Kansas City, MO 64108-2625 Phone: (816) 472-6100 Fax: (816) 472-1610 Toll-Free: (800) 848-APWA

Why are they called potholes?

Pottery makers in l5th and l6th according to the American Society for Civil What causes a pothole? century England would take ad- Engineers (ASCE) 2013 Reportcard on America’s Potholes are created when the top layer of vantage of the ruts that wagon Infrastructure. pavement and the material beneath—called the base or sub-base—cannot support the weight of and coach wheels gouged into Driving over rough pavement affects travel the traffic. Two factors are always present in such roads. Anxious for a cheap costs for motorists in terms of vehicle operating source of raw materials for costs, travel delays, and crash or accident costs. a failure: TRAFFIC and WATER. making clay pots, the potters Motorists paid an extra $444 a year in 2014 - a would dig into the deep ruts to total of $6.4 billion, according to AAA Mid- reach clay deposits underneath. Atlantic, in vehicle repairs and operating costs. For municipalities, pothole repair expenses include Teamsters driving wagons and personnel, equipment, and materials, and on a coaches over those roads knew national basis equates to a multi-million dollar who and what caused these annual expenditure. holes and referred to them as “potholes.” For example: • Driving on roads in need of repair and full of - Story attributed to the late trivia potholes costs motorists in Washington, D.C. The “gestation period” for a pothole includes: expert and syndicated columnist approximately $833 per motorist, or $311 1) Snow-melt or rain seeps through cracks in L. M. Boyd million a year, according to the American the pavement and into the sub-base; if the Society of Civil Engineers Report Card for moisture cannot adequately drain away from Infrastructure. the sub-base and soil underneath, it becomes • In 2013, the City of San Diego, CA. filled over saturated and soft. The North American love of the open road is 30,000 potholes, spending $1.3 million for 2) Trapped moisture is subjected to repeated tested every late winter and spring when millions pothole repair. freeze/thaw cycles–and with each occurrence of pavement potholes suddenly appear seemingly the expanding ice lifts and cracks the everywhere. Mobility is increasingly integral to our • In Oklahoma City, OK. The city spends $1 pavement more. The passing traffic weakens way of life. million to make repairs to as many as 90,000 the pavement, cracking it further. Did you know that 254 million registered vehicles potholes each year. 3) As temperatures rise and the ice melts, a void travel nearly 3 trillion miles on more than 4 million is left under the pavement. This void collects miles of streets and highways in North America? • In 2012, Columbus, OH. spent $175,578 for more water, and during the next freeze, the An estimated 32% of our major roadways are the hot and cold mix asphalt patch material void will enlarge. rated in poor to mediocre condition, and driving to patch 130,397 potholes. 4) Vehicles driving over the weakened on poor roads costs motorists $67 billion in pavement pound it until the surface breaks additional car operating and repair costs annually, and collapses into the void below, thus creating a pothole. paved streetorroad: The followingarethestandardpotholerepairmethodsusedforanyasphalt times whenweatherandtraffic aremoreconducivetosafeoperations. maintenance workers. Repairsthataremorepermanentcanbescheduledfor Emergency repairsusuallyaredoneinheavytraffic andcanbeasafetyriskto responsive totraffic demands. embedded loopsensorwires, andwhentheybreak, thesignals willnotbe slow-down andcongestion. Potholes nearactivated traffic signalsmayexpose it. Or, oneormorelargepotholeshindertheflowoftraffic causingunusual to collisionsbycausingdriversswerveavoidorlosecontrolafterhitting corrected. For example, alargepotholeonmajorarterialhascontributed a substantialsafetyortraffic operational problemandmustbeurgently periods. Typically, emergencyrepairsare doneonlywhenapotholepresents conditions, orasroutinemaintenancescheduledforwarmer anddrier Pothole patchingisperformedeitherasan emergencyrepairduringharsh How are potholesrepaired? equipment, andmaterials, andthedemandsoftraveling public. maintenance workorutilityintheroadway; availability ofpersonnel, weather; traffic conditions; imminentscheduledroadway construction; major The decisionandcapabilitytopatchpotholesisinfluencedby: current network andarenotexpectedtokeep pacewiththeincreaseddemand. few newlane-mileshavebeenaddedtothenation’s highway, roadandstreet Traffic volumehasincreasedsignificantlyandthistrendwillcontinue—but design andconstructionpractices, maintenanceactivity andpavementage. environmental conditions, topography, subgrade condition, initialpavement tire pressureandgrossvehicleweight[GVW]), traffic volumeandmix, Pavement lifeisinfluencedbymanyfactors: vehicleloading(axleloads, What affectspavementlife? 2. Hot-Patch Semi-Permanent: Water anddebrisareremovedfromthe 1. Cold-Patch (”Throw-and-roll”) : Patching materialisshoveledintothe the cost of theoperation, this isconsideredone ofthebestmethods for device. A slightcrownfor water dispersal isdesirable. Although itraises a heatedasphalt mixisplacedandcompactedwith asmall, vibratory sides existinreasonably soundpavement. Tack oilisappliedandthen pothole; thesidesofpatch area are “squared-up” untilvertical preclude amorepermanentrepair. fix performedwhentraffic, weatherandgeneral pavementconditions site.) Cold patchrepairsarequick, buttemporary; theyareanexpedient and-go”, whichdoesnotcompactthematerialsbeforeleaving considered superiortothemorecommonlyusedmethodof “throw- compacted ifpossible, andcrewmovesontonextpothole. (This is pothole—which mayornotbefilledwith water anddebris—and and soil. some cases, under-drains maybeinstalledtocarrywater away fromthebase back toordownsolidpavementbaseandthennewmaterialplaced. In usually requirebaserepairsatalatertime. The affectedareaisremoved Severely distressedspotsthataremuchwider, oraresubstantiallydeeper, Pavement Condition America, RepairPriorities2014.” of StateHighway and Transportation Officials(AASHTO) “SmartGrowth once ithasdeteriorated significantly, accordingtothe American Association in goodcondition, itavoids$6-$14neededlatertorebuildthesameroad repairs. Expertsconservatively estimatethatforevery$1spenttokeep aroad of deteriorating infrastructure andincreasinglycostlybacklogsofrequired In reality, deferredmaintenancecanstartcommunitiesonadownward path potholes fromformingandforextendingtheusefullifeofpavement. to keep water frominfiltrating intothesub-base iscriticalbothfor keeping potholes beginswhenthepavementisvisiblycracked. Sealingthepavement the repairandqualityofmaterialstechniquesused. Preventing The successofpotholerepairsdependspredominantly onthetimelinessof How canwestoppotholesfrom forming? 4. EdgeSealasfollow-up: Usessamemethodasthrow-and-roll, butonce 3. Spray-Injection Devices: Water anddebrisareblownfromthepothole; improve patchperformanceinolderpavementswithmanycracks.) are clearedfromthearea. (Althoughthisrequiresasecondpass, itcan and thesectionisopentotraffic assoonworkers andequipment A layerofsandisplacedonthetackmaterialtopreventtracking bytires, asphaltic tackmaterialontopofthepatchedgeandpavementsurfaces. repair sectionhasdried, asecondpassismadetoplaceribbonof material correctedbeforefilling. potholes. The materialisnotcompactednortheunderlyingbase patch; however, itisnotasdurable asorusefulhotpatchfordeeper injection isfasterthanhotpatchrepairsandmorepermanentcold but hasahigherrate ofproductivityandlowermaterialcosts. Spray with alayerofaggregate. This techniquehashigherequipmentcosts, asphalt andaggregateareblownintothepothole; thepatchiscovered a tackcoatofbinderissprayed onthesidesandbottomofpothole; traffic andweatherconditionsaremorefavorable. method ismorelaborandequipmentintensive, itisusuallydonewhen repairing potholes, becauseitimprovespatchperformance. Becausethis In Quality 40% Drop 75% ofLife In Quality 40% Drop Time in YearsTime before thispoint… pavement preservation Spending $1on 12% ofLife reconstruction here. rehabilitation or spending $6-$14on …eliminates ordelays