California Department of Transportation

Maintenance Program

Mission Statement

The Maintenance Program’s mission isto protect public safety and preserveCalifornia’s Highway System by main-taining and repairing the system andresponding to emergencies so travelersand goods reach their destination safelyand efficiently.

Values

• Our workforce• Customer’s time• Teamwork• Customer’s opinions and needs• Financial resources• Our commitments• Commerce and the economy• The environment• Continuous improvement/quality• Innovation

Caltrans Snow Districts Map . . . . . . . . . . . . . . . . . . . . . . . . . 2

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Caltrans Snow and Ice Policy . . . . . . . . . . . . . . . . . . . . . . . . 3

Chain Control Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

• Chain Control Requirements . . . . . . . . . . . . . . . . . . . . . . . 5

Clearing the Roadway Surface . . . . . . . . . . . . . . . . . . . . . . . 7

• Environmental Concerns. . . . . . . . . . . . . . . . . . . . . . . . . . . 7

• Alternative Deicing Materials . . . . . . . . . . . . . . . . . . . . . . 8

Snow and Ice Control Equipment . . . . . . . . . . . . . . . . . . . . 10

• Snow Removal Personnel Management . . . . . . . . . . . . . 11

• Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

• Weather Forecasting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

• Enforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Avalanche Control Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Improvements in Snow and Ice Control . . . . . . . . . . . . . . 15

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

For More Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

CALIFORNIA DEPARTMENT OF TRANSPORTATION

1

Caltrans Snow Districts

MODOC

LASSEN

SHASTA

TEHAMA

TRINITY

PLUMAS

SIERRA

NEVADA

PLACER

EL DORADO

AMADOR

CALAVERAS

ALPINE

MONO

BUTTE

YUBA

SUTTER

COLUSA

YOLO

STANISLAUS

MERCED

FRESNO

MADERA

MARIPOSA

TUOLUMNE

INYO

TULARE

KINGS

KERN

VENTURA

LOS ANGELES

SAN BERNARDINO

RIVERSIDE

IMPERIAL

SAN JOAQUIN

GLENN

SISKIYOU

SACRAMENTO

2

3

10

9

6

7

8

District Snow Route Miles*(Above 2,000 Ft. Elevation)

SNOW DISTRICT MILES

2 1,2803 413

6 1777 235

8 5979 1,014

10 351*Centerline Miles

2

Introduction

The following isCaltrans’ officialpolicy on snow andice removal from statehighways:

“Snow removal and icecontrol shall beperformed as necessaryin order to facilitatethe movement andsafety of public trafficand shall be done inaccordance with thebest managementpractices outlinedherein with particularemphasis given toenvironmentallysensitive areas.”1

The California Department of Transpor-tation (Caltrans) has been given statu-tory authority for the planning, design,construction, operation, and mainte-nance of California’s State HighwaySystem. A key component of the mainte-nance of certain highways is the controlof snow and ice. Caltrans maintenanceforces strive to provide a safe travel wayduring winter conditions while keepingtraffic delays to a minimum. However,Caltrans must also consider the environ-mental issues of snow and ice controlactivities. Compounding this is thetraveling public’s expectation that highlevels of service are to be maintained,

1Adopted July 1992.Outlined in CaltransReport to theLegislature inresponse to Chapter318, Statutes of 1991(Hauser), “The Useof Deicing Chemicalson California StateHighways” July,1992.

even though a route is subject to snowand ice conditions.

The large geographical area that com-prises the State of California includesmany different climate zones. Conse-quently, motorists from warmer anddrier parts of the state may be unpre-pared for the challenges of driving in thesnow during the winter.

This booklet will describe variousaspects of Caltrans’ methods of control-ling snow and ice on mountainoushighways.

Caltrans Snow and Ice Policy

Rotary snow plow

3

Chain Control Operations

AUTOS & P I C KU PS S N OW T I R E S O K

CAR RY CHA I N S

C HA I N S R E Q U I R E D

S P EED L I M I T

2 5

ON S I N G L E AXLE D R I V E VEH I C L E W I T H T RA I L E R

C HA I N S R E Q U I R E D

S P EED L I M I T

2 54-W D R I V E W I T H S N OW T I R E S O K

CAR RY CHA I N S

C HA I N S R E Q U I R E D

S P EED L I M I T

2 5

NO EXECPTIONS

CHA I N S R E Q U I R E D

S P EED L I M I T

2 5

Snow and ice control is important onevery mountainous route within Califor-nia; however, certain routes carry heavyseasonal recreational traffic as well ashigh volumes of truck traffic. Theseroutes require extensive snow-fightingactivity to keep open during heavy snowstorms. This can be compounded by thefact that many motorists driving in theseareas expect to be able to drive the sameway they do in the summer. Also, many

motorists are reluctant topull off the traveled wayand “chain-up.”

Long traffic queues are notuncommon during stormson major transportationroutes to and from recre-ational areas. In areas wheretraffic congestion has be-come a major factor intravelers’ safety and snowremoval efforts, provisionshave been made to “meter”traffic. Traffic metering isperformed at lower eleva-tions below the snow lineduring chain control opera-

tions. Metering controls the volume oftraffic during peak periods over snowroutes, allowing smooth flow of trafficand maximum snow removal effort.The metering is con-ducted where food, fuel,and restrooms areavailable to temporarilydelayed motorists.

Caltrans has defined thefollowing chain controldesignations for variousroad conditions duringsnow storms:

R1a (Modified R1) Chains required forsingle axle drive vehicles withtrailers.

R1 Chains required, except for autos orpickups with snow tires.

R2 Chains required, except for vehicleswith four-wheel drive and snowtires on four wheels. (Must carrychains.)

R3 Chains required; no exceptions.(Note: R3 conditions are rare — theroad is usually closed prior to thisdesignation.)

The illustrations at left show the typicalsigns used by Caltrans for the chainrequirements described above.

CHAIN CONTROL REQUIREMENTS

It is Caltrans’ responsibility to determineand post chain requirements. CaliforniaVehicle Code specifies and defines “TireTraction Devices.” Traditionally, thesedevices have been made of steel chain.

Studded tires, while legal for use onhighways during winter months, donot qualify as an approved “TireTraction Device.”

These signsare typical,although insome areas thespeed limitsign is notincluded.

Winter traffic

4

Cable type chains are approved inCalifornia when used per the properapplication (see Figure 1). However,during extreme conditions, large trucksusing cable chains may be held untilconditions permit safe travel.

Cars and pickup trucks equipped withmud and snow tires (as alternativetraction devices) are acceptable duringR1 chain control conditions.

1

��z|�| �

�yz��z|

��z|��{|��y{��{|

1F 2 3 4

5

8

5 ��z|��{| 6

��yz���yz{

10

��{|�z

7

��z|���z{|

11��y{��yz9 ��yz��z|���yz|

12

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15���y{|��y{

STATE OF CALIFORNIA DEPARTMENT OF TRANSPORTATION

Chain Requirements

AUTOS/PICKUPS

LEGEND

NOTES

BUSES/RECREATIONAL VEHICLES

TRUCKS

The following vehicles are permitted in chain control areas when equipped with chains or an Automatic Traction Device (ATD) as indicated.

The Department of Transportation reserves the right to prohibit any vehicle from entering a chain control area when it is determined the vehicle will experience difficulty in safely traveling the area.

• All vehicles towing trailers must have chains on one drive axle.

• Trailers with brakes must have chains on one axle.

• Front wheel drive vehicles must have chains on front (drive) axle.

• House trailers may be prohibited in severe snow conditions.

• On any semi-trailer, only one set ofchains is required regardlessof number of axles.

• Chains are not required on tag axle.

16 ��yz���yz|

Tractor, Semi-trailer, and Trailer Type 2-S-1-T-2Tractor, Semi-trailer, and Trailer Type 2-S-2-T-2

Truck Type 3 (with front drive axle)

Truck and Trailer Type 3-T-3 or 3-T-2Tractor, Semi-trailer, and Trailer Type 3-S-2-T-2

Monotrailer Type 3-AS2Tractor and Semi-trailer Type 3-S-2

Truck Type 3

Type 2 Type 3

(Articulated buses must also chain outside wheelsof last axle.)

Tractor and Semi-trailer Single Dr.Truck Type 2 (Caltrans may require chains on all drive wheels if conditions warrant.)

14���y{|�{Tractor, Semi-trailer, and Trailer Type 2-S-1-T-2

The following trucks may be restricted when chains are required:

Driving axleNon-driving axleWheel with chainsWheel with chains or ATDWheel with no chainsChains required on insidedual if possibleDrive axle must be chainedChains on trailers may be staggered front and back

��yz��y{or Acceptable on either axle

of semi-trailers

Revised 10/94

Figure 1

Four-wheel drivevehicles one tonand smaller withsnow tires (asalternative trac-tion devices) on allfour wheels areacceptable duringR2 chain controlconditions.

Truckin’ on the east slope of the Sierra Nevadas

5

7%

During R1 or R2 conditions, all vehiclesincluding four-wheel drives that arepulling trailers must chain at least onedrive axle. If the trailer is equipped withbrakes, one of the trailer’s braked axlesmust be chained also.

To aid truck drivers in the proper chain-ing of their vehicles, Caltrans pro-vides the chain requirement chartto drivers at most weigh stationsleading to mountainous areas.

On most major routes Cal-trans provides personnel tocheck all vehicles at chain controlpoints. On other routes theregulatory signs are de-ployed by Caltranspersonnel, then leftunattended.

Chain controls are generallyused during snowstorms andusually end soon after the endof the storm. However, withsunshine, the snow and ice packwill begin to melt resulting in slush onthe pavement that is difficult to negoti-ate without tire chains. Isolated shadyspots can remain frozen well into theday and can be effectively treated withlight applications of deicing salt or saltsubstitute and sand, thereby allowingchain controls to be dropped.

Due to restricted tire clearances andpoor traction, certain types of vehiclespresent a challenge to chain controlpersonnel at the check points. Theseinclude single drive trucks pullingdouble trailers, commercial auto carriers,three-axle tractors with single drive andnewer front wheel drive vehicles that are

restricted from chain use per theirowner manuals. These vehicles are

often held or may be turned backuntil road conditions improve.

Many motorists are unfamil-iar with driving in snow

and ice conditions andare likely to drive toofast for the conditions.

Caltrans reserves the rightto prohibit any vehicle or

combination that it deems unsafefrom traveling inside a chaincontrol area.

Certain sections of low trafficvolume mountainous routes (i.e.,

State Routes 4, 120, 108, and others) areclosed during the winter season be-cause Caltrans has made the determi-nation that safety concerns coupledwith low traffic demands do not justifythe high cost of keeping these routesopen during the winter.

Carving a path through the Sierra Nevada mountains

6

Clearing the Roadway Surface

Caltrans utilizes snowplows and motorgraders for clearing snow from theroadway surface. Deicing salt is theprimary agent for ice melting and break-ing the bond between the snow pack andthe pavement. Abrasives, such as sandor volcanic cinders, are spread in orderto provide better vehicle trac-tion. In some areas salt isapplied separately from abra-sives in order to better controlthe location and applicationrate. This has proven to signifi-cantly reduce the amount ofsalt used.

District directors are respon-sible for the judicious use ofsalt and other chemicals forsnow and ice control. Throughoperator training and usagelogs, the Department hassignificantly reduced the amount ofapplied deicing salt. Without the use ofan effective deicer such as salt, Caltranswould need to require more frequentand extended use of chains by motoriststravelling mountainous routes in thewinter. The use of chains, which requireslower vehicle operating speeds, com-bined with the operational problems

presented by motorists stopping on thetraveled way to install chains, signifi-cantly reduces the capacity of the high-way. Another problem faced is that chainuse on mountain highways contributes topavement wear and deterioration of ridequality.

The control of ice and snow onmountainous routes involvesbalancing the needs of thetravelling public, traffic andpersonal safety, and the protec-tion of the environment.

ENVIRONMENTALCONCERNS

Although there is by no meansa consensus of opinion amongexperts as to the magnitude ofdamage caused by the applica-

tion of deicing salt, it is believed thatdeicing salt does cause some vegetationdamage, as well as bridge deck andvehicle underbody corrosion.

In recognizing the potential for thesekinds of harmful effects, Caltrans hasimplemented a reduced salt-use policydated October 1989 and required thetransportation districts to developspecific route by route plans. In thewinter of 1989/90, Caltrans reduced saltusage by 62 percent statewide as com-pared to the previous winter. This wasmade possible by the combination of amild winter and improved control of theapplication frequency of deicing salt.

Lake Tahoe basin

7

The State of Nevada Department ofTransportation, in cooperation withCaltrans, retained a private research firmto study the impacts of roadway deicingsalts on vegetation within the LakeTahoe Basin. This study, published in1990, concluded that of 5,450 treesobserved along the Lake Tahoe Basinhighways within both Nevada andCalifornia, 15 percent of the trees weresalt-affected. The majority of the dam-aged trees surveyed showed evidence ofdisease, bark beetle infestation and theeffects of four years of drought.2

In addition, there is concern that deicingsalt could be degrading local watersupply sources in the Lake Tahoe Basin.In this regard, the Lahontan WaterQuality Control Board issued boardOrder No. 6-89-139A directing Caltransto perform water quality testing ofcertain Lake Tahoe area streams on aregular basis.3 Caltrans annually reportsback to the Lahontan Water QualityControl Board.

Another environmental concern is theusage of sand and its effects on air qualityfollowing storm conditions. Dust fromairborne particulate matter is generatedby vehicles driving over drying sand.

Caltrans has implemented several pro-grams including immediate sweeping ofsand deposited during a storm and the

application of hydroscopic materials tothe sand to attract moisture and elimi-nate dust from high-speed traffic. Bothof these practices have proven to beeffective. Caltrans is continually search-ing for materials, and improved opera-tional practices to lessen the effects tothe environment from our snow removaloperations.

ALTERNATIVE MATERIALS

Caltrans, in response to the requirementsof Assembly Concurrent Resolution 96(Waters), evaluated several alternativesto deicing salt during the winter of 1989/90. In a report to the members of theCalifornia Legislature,4 Caltrans re-ported that it had been testing two majoralternative deicers, calcium magnesiumacetate (CMA) and magnesium chloride.A summary of the results of the testingof these two materials follows:

Calcium Magnesium Acetate (CMA)

CMA was utilized on various routessubject to heavy snowfall in MonoCounty in District 9. In addition, it wastested in small amounts on test sectionsin Northern and Central California.During these tests, it was found thatCMA was less effective than salt fordeeper snow packs and does not pen-etrate the pack as rapidly as salt, whichresults in a delay in the melting of ice

2“Roadside ErosionControl andRevegetation NeedsAssociated With theUse of Deicing SaltWithin the LakeTahoe Basin,”Resource Concepts,Inc. (September1990)

3 “Report forMonitoringProgram per BoardOrder 89-139A,Æ”Lahontan WaterQuality ControlBoard, CaliforniaDepartment ofTransportation(February 14, 1990)

4 “Evaluation ofDeicing Substituteson Certain RoutesDuring the 1989-90Snow Season,”CaliforniaDepartment ofTransportation(July 3, 1990)

8

and snow pack, particularly at tempera-ture below 24 degrees F. CMA does,however, change the consistency of thesnow pack so that it is easier to plow.

CMA can cause respiratory distress andeye irritation for personnel required tohandle it, thereby necessitating the useof protective gear. CMA costs about $600to $700 per ton as compared to saltwhich costs less than $50 per ton. An-other problem with CMA is that ittypically needs to be spread at about 1-1/2 times the rate of salt to be effective.

Magnesium Chloride

Magnesium chloride was tested on a5-1/2 mile section of Interstate 80 nearDonner Summit. At the end of storms,bare pavement was achieved moreuniformly than with salt. Magnesiumchloride was found to be as effective atlower temperatures as salt. Magnesiumchloride, being a liquid, can be appliedin a more uniform manner than granularsalt, but must be kept in storage tanks.One of the drawbacks of magnesiumchloride use is the fact that it should notbe used on the travel way when snowpack is over 1/4 inch in depth. Applica-tions on pack over that depth havecaused the road surface to becomeslippery due to fast melting followed byre-freezing, necessitating additionalsanding and magnesium chloride treat-ments to eliminate the problem.

Liquid magnesium chloride appears tobe a viable substitute for salt; however, ithas been shown to be most effective asan anti-icer at lower elevations wherefrost has been a problem. Its residualeffects in these areas makes it easy toapply pre-storm with re-applications notneeded for several days.

Caltrans is planning to continue the useof liquid magnesium chloride, and otheralternative deicers, in an effort to reducethe use of salt.

Caltrans anticipates that deicing salt willstill be needed in the future, even withthe use of alternative deicers, because ofits cost-effectiveness and the low envi-ronmental impact in most areas of use.Caltrans districts will judiciously usesalt for snow and ice control; by balanc-ing the need to protect the environmentwith providing the best service to ourcustomers.

Slip-in sanding boxes in storage

9

Snow and Ice Control Equipment

Although deicing materials (salt, magne-sium chloride, etc.) are useful in thecontrol of snow and ice, snowplows andmotor graders are often required to clearsnow and ice from the roadway surface.Rotary snow plows are necessary tomove snow off the travel way in largequantities and clear storage areas.Although equipment and methods varyaccording to local conditions, the follow-ing is a brief description of Caltransequipment used to control snow and ice.

Caltrans typically uses four-, five-, andten-cubic yard capacity trucks with pushplows.

In some areas, Caltrans crews utilizetrucks with wing plows that enableclearing a wide area (up to 22 feet) in asingle pass. The wing plow is hydrauli-cally extended from the side of the truckby the operator. Most trucks with plowsalso have the ability to spread salt orsand while plowing. Mosttruck-mounted plowsoperate at about 30-35mph. Trucks equippedwith these plows costabout $40 per hour tooperate including operator.

Caltrans also uses motorgraders to a large degree.Motor graders used for

snow and ice removal have both frontand moldboard blades which enablethen to plow wide areas. Motor graderscan apply considerable downwardpressure (with the moldboard blade)which makes them very effective atcutting hard snow/ice pack. In areaswith large snowfall amounts or thathave miles of snow pack conditions, themotor grader is the operations “work-horse.” They push huge quantities ofsnow and remove snow pack from thetravel way. However, great care needs tobe used by the operator, as they cancause significant damage to flexiblepavements if not closely monitored.With the advances of all-wheel drive andarticulated units into our service fleets,the speed and efficiency of these unitshave become remarkable. These ad-vances have also increased operatorcomfort and control, essential for long

Rotary snow plow blowing snow

10

shifts and slippery roads. Due to theslower speed that they work at, they dotend to slow traffic down as it maneu-vers around them. On most multi-lanehighways, motor graders work in teamsof two or three, staggered to allow trafficto maneuver through them, to avoidtraffic back ups. Serrated blades havebeen used in some areas on the mold-board with success for the removal ofstubborn ice and snow pack. Motorgraders cost about $60 per hour tooperate.

Rotary snowplows are used to blowpiles and windrows of snow left byplowing out of the snow storage areas,as well as cutting through deep snow.Several of our larger rotaries have theability to remove up to 5,000 tons ofsnow per hour. Rotary plows also havethe ability to direct the snow blown outof the chute away from fixed objects,such as roadside signs. The rotary plowsoperate at a much slower speed thantruck-mounted plows and motor graders(about 3-5 mph). Rotary plows costabout $120 an hour to operate.

SNOW REMOVAL PERSONNELMANAGEMENT

Due to the seasonal nature of snow andice control operations, Caltrans employsa large number of temporary employees.In addition to these seasonal employees,some members of other maintenancearea crews are called on to assist in theseoperations. In rural areas, some districtsuse dormitories built along major routesto provide food and housing for employ-ees that are temporarily assisting withsnow removal activities. Some tempo-rary staff members are local residents;others stay at local motels. Crews fromnon-snow areas of California are utilized

Roadeo events

to assist inmany areas tofortify localsnow crews.

EquipmentRoadeo

One method ofenhancingCaltrans’snow-crewtrainingprogram is theEquipmentRoadeo. Thiscompetitiveevent, which isheld annually,promotessafety andprofessional-ism in snowremovaloperations.Events in-clude: tirechain installa-tion/removal;detailedvehicle pre-trip inspection; operation ofplow trucks, motor graders and front-end loaders on an event course.

Caltrans districts conduct local qualify-ing events with finalists competing atthe annual statewide Roadeo. Althoughcontestants must use their personal timefor these events, Caltrans feels that thefriendly competition will improveoperator performance and professional-ism as well as foster “esprit de corps.”Recently, Caltrans’ top operators haveperformed well at the National Roadeoheld in Colorado, including several firstplace finishes in 1998.

11

ROAD CONDITIONSWithin California

1-800-427-7623 (ROAD)Outside California

916-445-7623

Road Weather Information System

12

COMMUNICATIONS

In order to provide motorists withcurrent information on highway condi-tions, Caltrans updates the CaliforniaHighway Information Network (CHIN)phone numbers 24 hours a day.

Caltrans also provides up-to-date high-way information on the Internet at thefollowing address: http://www.dot.ca.gov/hq/roadinfo.

In order to provide motorists withcurrent information, district maintenancepersonnel report current conditions tothe district dispatch office, which in turninforms the Headquarters MaintenanceCommunications Office. In addition toCHIN and the Internet, Caltrans usesHighway Advisory Radios (HAR) alongmany routes to provide motorists withlocal road and traffic information. Thereare also Changeable Message Signs(CMS) permanently located along manyroutes to advise motorists of currentconditions. Portable CMS are also usedat strategic locations as needed, to adviseof road and traffic conditions.

WEATHER FORECASTING

Caltrans relies on storm forecasts fromthe National Weather Service, varioussources on the internet, and a few con-tracted weather forecasters. Districtdispatchers advise maintenance crews ofimpending snowstorms via telephone or

radio and follow with a facsimile (FAX)of the entire forecast. Some maintenancesuperintendents and supervisors tele-phone the National Weather Servicedirectly in order to share informationconcerning local conditions. Weatherinformation via contracted satelliteservice is also utilized. This serviceprovides, real-time radar, satellite, andwritten weather updates via satellitelink. This type of service has been veryreliable for reception of weather infor-mation when weather conditions havecaused power and telephone outages.These types of real-time informationsystems have enabled snow crew super-visors to more accurately predict thetiming and nature of storm cells. Thisenables more precise control of deicerapplication timing, as well as determin-ing appropriate staffing levels, chaincontrols and traffic management whilea storm passes through the area.

In some areas, Road Weather Informa-tion Systems (RWIS) are available toprovide local pavement and atmo-spheric data.

ENFORCEMENT

Caltrans has the responsibility fordetermining when chain controls arenecessary, informing motorists of therequirements, and inspecting vehiclesfor conformance to the requirements.The enforcement of the chain require-ments is the responsibility of the Califor-nia Highway Patrol (CHP). The CHPoften will station a unit (an officer andvehicle) at the chain control point. Inaddition, CHP units may patrol thesection of the route under chain controlrestriction. The California Vehicle Codespecifies a basic fine for violation of

5 CaliforniaVehicle CodeSection 22363.

*GAZ-EX is atrademark ofSchippers S.A.

Avalanche Control Areas

chain control requirements. Additionally,local jurisdictions may add additionalcourt costs and fees.

In addition to enforcing chain require-ments, the CHP also aids Caltrans inassuring the expeditious and orderlyflow of traffic through the chain controlarea. Caltrans has the authority to setreduced speed limits of either 40, 35, 30,or 25 miles per hour, whichever is foundmost appropriate for the prevailingconditions.5 The enforcement of postedspeed limits within the chain controlarea is a CHP responsibility.

Avalanches pose asubstantial threat tothe safety of thetraveling public andCaltrans mainte-nance workers. Tocontrol avalanches,Caltrans or theiradvisors perform snowsurveys in knownavalanche areas to deter-mine the likelihood of anavalanche. Once the determi-nation has been made that anavalanche is threatening, spe-cially trained maintenance person-nel close the highway until theavalanche can be safely released.

THE GAZ-EX SYSTEM

Caltrans uses the GAZ-EX* systemdeveloped by Schippers, S.A. of LeTouvet, France for the majority of itsavalanche control. The GAZ-EX utilizes

Avalanche Control Areas

U.S. 50 at Echo Summit, Eldorado Co.

Route 158 at June Lake, Mono Co.

Route 88 at Red Lake, Alpine Co.

Route 88 at Carson Spur, Alpine Co.

13

stored propane and oxygen piped into afixed cannon located in an avalanchestarting zone, directing a blast towardthe ground. The system is remote con-trolled and is considered to be moreeffective and have a higher factor ofsafety than any other currently availablesystem. These units have been placedthroughout the state to control areas thathave had historical avalanche problems.

LoCAT* commercially made artilleryguns are available as a back up to theGAZ-EX system. The LoCAT units arereplacements for the outdated U.S.military 75 mm recoilless rifles that wereretired from active duty with Caltrans in1997. The LoCAT system utilizes com-

pressed air to propel a seven-poundexplosive payload to the target area. Weare continually looking for lower cost,more effective solutions to avalanchecontrol to improve operational safety andproductivity.

In some parts of the state, for close rangeavalanche control work, a low-pressureinert gas propelled projectile is firedfrom the Avalauncher.** This device haslimited range, but is simple to operate ata relatively low cost.

The last resort in our avalanche controlarsenal is the deployment of explosivehand charges. This operation is verytime consuming and requires trainedand certified personnel. These hand-charging operations often take placeduring the most extreme conditions onthe snow laden cornice areas overlooking the highways. Dedicated em-ployees apply their special skills in handthrowing these charges to release ava-lanches in areas where other methodsare not effective or available.

GAZ-EX avalanche control cannon

LoCAT avalanche control system

14

* LoCAT is atrademark ofSSE, Inc.

**Avalauncher is atrademark ofAvalancheControl Systems.

Improvements in Snow

and Ice Control

Caltrans is always looking for newmethods and equipment to improve itssnow and ice control operations.

The use of trafficsensing equipment,such as pavementloops, in the travelcorridors leading tothe mountains couldprovide importanttraffic data to chaincontrol points. Thisdata could be useful tomanage traffic entering a chain controlarea, allowing for more efficient plowingand traffic movement.

Wire-guidance systems embedded in thepavement on sections of highways thatexperience winter closures are beingused and evaluated. These systemsenable snow plow operators to safelyreopen the closed road by indicating theplow truck’s location on the snow-buried roadway.

A Global Positioning System (GPS)vehicle guidance system is currentlybeing installed and tested in several

places in the state. One of these systemswill be evaluated on Interstate 80 overDonner Summit to see if it has value in

assisting motoristsand snow removalequipment whiledriving and workingin poor visibility.

In a related applica-tion, a structure calleda “jet roof” is installedon the top of a ridgenear Carson Pass on

Route 88. The “jet roof” alters the windpatterns that normally blow across theridge area creating dangerous snowcornices. If not prevented, these cornicescan suddenly give way in an avalancheof snow onto the highway below.

Currently under development is asystem to measure snow removal levelof service. Caltrans believes that byconsistently measuring we can imple-ment performance-based adjustments topersonnel, equipment, and materials.Cost savings, improved service to ourcustomers, and safer winter travel arethe goals of this program.

Close-up of jet roof (above); Jet roof array above Carson Pass (below)

15

Conclusion

References

1. Maintenance Manual, Volume One,California Department of Transporta-tion (June 1998)

2. Snow Fence Guide, Strategic HighwayResearch Program (October 1991)

3. The Use of Deicing Chemicals on Califor-nia State Highways, Caltrans Report tothe Legislature in Response to Chap-ter 318, Statutes of 1991 (Hauser)

4. Evaluation of Deicing Substitutes onCertain Routes During the 1989-90 SnowSeason, California Department of

The maintenance of California’s high-ways is increasingly challenged in thathigher public expectations and increas-ing traffic are complicating operations.

In order to maintain satisfactory levels ofservice, Caltrans must strive for maxi-mum effectiveness from its crews,equipment and materials. The snow andice control program is no exception.

Caltrans will strive to incorporate newproducts and techniques into snow andice control. Increased training opportuni-ties for snow and ice control personneland improvements in traffic manage-ment and information systems willmaximize the utilization of providedresources while protecting the safety ofthe traveling public, maintenance per-sonnel and the environment.

Transportation, Report to the Legisla-ture as Required by Resolution Chap-ter 157, Statutes of 1989 (ACR 96Waters) July 1990

5. Roadside Erosion Control and Revegeta-tion Needs Associated With the Use ofDeicing Salt Within the Lake Tahoe Basin,Resource Concepts, Inc. (September14, 1990)

6. California Vehicle Code, CaliforniaDepartment of Motor Vehicles

For More Information

Mr. Kris Kuhl ...................... (916) 654-5789Mr. Jack Tonkin .................. (916) 653-2143Mr. Stan Richins ................. (916) 654-2711

http://www.ca.gov.hq/roadinfo

IMMSIMMSPROJECTPROJECT

Office of IMMSProject and SpecialStudies, including:• Snow and Ice Control• Major Damage Restoration

Motor grader at work

16

Within California1-800-427-7623 (ROAD)

Outside California916-445-7623

Callers can use a touch-tone phone for recorded messages on road conditions. After dialing, enter the route number

and touch the pound sign (#).

California Relay ServiceTTY 1-800-735-2929

Internet Accesshttp://www.dot.ca.gov

For information while in Western Nevada – from Reno, Sparks, Carson

City, North and South Shore Lake Tahoe

(702) 831-6677

RoaRoad Condd Condititionionss

LLististen to ten to thhe Sige SignsnsIn all weather conditions, Caltrans highway workers need your help. Always remember:

Slow down when passing a work area. Stay alert and leave enough time for travel. Pay attention to the signs.Be careful. Just like you, Caltrans workers want to return home safely tonight.Maintain control of your vehicle. Stay focused on the job at hand – driving safely.Obey all warning signs and watch for equipment. Workers may be nearby.

NEVER drive while under the influence of drugs or alcohol.

Gray Davis, GovernorState of California

Maria Contreras-Sweet, SecretaryBusiness, Transportation and Housing Agency

José Medina, DirectorDepartment of Transportation

PUBLISHED BY

Department of TransportationMaintenance Program

Randell H. Iwasaki, Program Manager

MARCH 1999

Photography and Graphics by Caltrans Graphic Services