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NEW JERSEY DEPARTMENT OF TRANSPORTATION

MODEL FOR

WINTER EQUIPMENT & MANPOWER ALLOCATIONS

2005

Re-typing of March 1978 Issue

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“NEW JERSEY D.O.T. MODEL FOR WINTER EQUIPMENT AND MANPOWERALLOCATIONS”

Forward

The Chief Engineer, Construction & Maintenance, directed that a Task Force beformed with the Chief of the Bureau of Maintenance to act as chairperson for the purposeof developing the required equipment and manpower allocation needed for snow removaland ice control operations.

TASK FORCE

Chairperson

Secretary

Members

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TABLE OF CONTENTS

Page Number

Problem Statement 4

Abstract 5

Conclusions 9

Action Taken 10

Further Recommendations 11

Appendix I 12

Spreading Formula 14

Loader Formula 16

Spreading Chart for Equipment 17

Appendix II 18

Plowing Formula 18

Plowing Chart for Equipment 21

Plowing Standards Diagrams 22

Appendix III 26

Personnel Requirements Formula 26

Personnel Requirements Chart 27

Appendix IV 28

Equipment: Truck Distribution 28

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PROBLEM STATEMENT

What equipment and manpower is required for Winter Maintenance Operations,

snow removal and ice control to meet New Jersey’s policy of “wet pavement as soon as

economically feasible after the storm?”

To develop an equitable allocation of existing equipment to meet regional

demands with reference to the number, type and age distribution of the truck fleet.

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ABSTRACT

The Equipment and Personnel Task Force met periodically over an eight-month

period and during that time developed formulas applicable to spreading by State forced,

plowing by both State and contractual forces, manpower to spread on a shift basis and a

distribution percentage to apply to the assignment of new trucks whether they be

replacements or new equipment.

Formula for Spreading

The basic concept of the following formula is to complete the initial statewide

spreading application of chemical de-icers within one and one-half hours. Taken into

account in this formula is the speed of the vehicle (spreading and not spreading), long

two-lane sections, short multi-lane sections, and the additional time consumed for

spreading ramps.

S = .4C + .9 [L + 2.5R]

S = Adjusted Lane Miles SpreadC = Center Lane MilesL = Roadway Lane MilesR = Ramp Lane Miles

The above formula is further modified to reflect the age of the existing fleet. The

data supplied indicated an average 80% up time for our truck fleet. This formula is as

follows:

(S’) = (S) times 1.25

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Once (S’) has been determined the following truck formulas can be used. The

mix of trucks is adjusted to meet the requirements of each foreman’s section.

T = S’ = Total of 2.5 Ton Trucks needed to spread (S’)2.5 22

T = S’ = Total of 6 Ton Trucks needed to spread (S’)6 36

T = S’ = Total of 10 Ton Trucks needed to spread (S’)10 62

The criteria used for the number of loaders required for spreading operations is

equal to the sum of mainline lane miles plus the ramp lane miles divided by 150.

Number of Loaders Required = L+R150

Formula for Plowing

Similar to the spreading operations, a plowing formula was developed on the

premise of completing one entire clearing of snow from the roadway within a two hour

time period. The formula is as follows:

P = L + E + 2.5R7.5t

P = The number of plow trucks requiredL = Lane MilesE = Shoulder miles (Over 5’ in Width)R = Ramp Lane Milest = 2 hours

This formula allows for the increasing of plowing time which in effect decreases

the number of plowing trucks required. This is of considerable importance because of the

increasing difficulty of hiring private contractors to plow snow in certain areas of the

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State. This formula will allow the Department to formulate a policy as to the amount of

time acceptable to clear the roadway of snow.

As a result of the application of this formula, it became evident that certain areas

in the South Region cannot economically meet the two-hour plowing time criteria. There

are no contractors available in this area and it is not economically feasible to purchase

additional trucks to meet this need. A more realistic period of three or four hours should

be established for this area.

Personnel Requirements for Snow Operations

Personnel requirements are based on one man to a truck on a twelve hour

rotational shift basis. Taken into account is benefit time and attrition, because turn over

of employees is a way of life in Maintenance and should be recognized as such.

(M) = (A) + (B) + (W)

M = Employees RequiredA = Personnel Required to man the Spreading Vehicles

based on the adjusted spread (S) plus Loader Operators.(For a 24 hour coverage – multiply the personnel by 2.)

B = The Benefit Time which is 20% x (A)W = The Attrition which is 8% x (A)

Truck Assignments

A distribution percentage was established for each Region for 2 ½ ton, 6 ton and

10 ton dump trucks. Taken into consideration was the use of 2 ½ ton, 5 man cabs, needed

in regular maintenance functions. Using this percentage, new trucks will not be assigned

according to the set percentage. This will create an equitable fleet age distribution for

each region.

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Summary

The previous information is a valuable tool in budgeting, especially in the area

where new highways are opening to traffic. By applying the above formulations,

additional equipment and manpower required for winter operations can be determined

when the project is in the design stage. To keep a program such as the one established, it

will be necessary to perform periodic reviews to include additional mileage in the

inventory, crew headquarter relocations, additional crews and any physical or policy

changes that would affect the data.

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Conclusions

This study indicated that:

1. These exists a shortage in the total number of trucks and loaders available forsnow emergency operations.

2. There were inequities in the existing distribution of trucks for snow and icecontrol operations. These inequities existed both inter-Regional and intra-Regional.

3. While the average distribution by age appeared equitable, there exists someuneven distribution of vehicles for any one model year.

4. The problem of equipment “down-time” could be lessened by initiating a morerealistic replacement cycle for dump trucks. We are currently on an eight-yearreplacement cycle.

5. The need for contract “snow plowing” to supplement our fleet is justified.

6. Due to the inability to obtain adequate contract plowing services in some areas ofthe state, a decision will have to be made to either; a) accept a longer period oftime for the pavement to be cleared of snow, or (b “over-equip” those sectionswith state trucks in order that they may complete plowing operations within thespecified time.

7. The need for hired loaders was verified.

8. Taking into consideration split shifts and employee benefit time, we areapproximately 100 men short for statewide spreading operations.

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Action Taken

1. Trucks will be reallocated based on spreading and plowing formulas developed bythis committee subject to total available trucks.

2. The need for light graders and rollers, used to re-grade unpaved shoulders andunpaved institutional roads, has decreased to a level that allows the cross-tradingof 21 light graders and 2 rollers in the replacement program for trucks.

3. The age of the truck fleet will be adjusted so that in future years each Region willreceive an allocation of new trucks based on the percentage of the total trucks ofthat class in each Region.

4. Some contractor plowing sections have been adjusted based on the dataformulated in this report.

5. Funds were re-apportioned into Equipment procurement accounts to purchasetwenty additional six-ton dump trucks.

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Further Recommendations

1. There should be periodic reviews as new inventory is added to the roadwaysystem.

2. The data developed by this study should be used for budget purposes to documentshortages that still exist.

3. Establish a computer program based on this study with inventory updatingcapabilities. The output documents should be made available semi-annually on atimely basis to coincide with the budget preparation and preparation for the snowseason.

4. That top management be advised that there are certain areas in the state wherecontract plowing services are not adequate. In these areas it will require a longerperiod of time for Department equipment to remove snow from the pavement.

5. That an Equipment Review & Development Committee be established. Thepurpose of this committee would be to provide field recommendations for newequipment purchases. That members of this committee represent the Bureau ofMaintenance, Bureau of Equipment and each of the Regions.

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APPENDIX I

Spreading

Although New Jersey is located in the northeast, it normally does not receiveheavy snowfall accumulations. With this in mind, coupled with our high traffic densities,spreading of de-icing chemicals is of prime importance during the winter months. This iswhy the task force elected to meet and solve this problem first.

The approach was to design a formula or a series of formulas that would establishthe number of trucks required, without reloading to spread the entire state with de-icers.

In order to establish such a formula, it was decided to reduce the amount ofVariables and set up certain constants as follows:

1. Rate of spread = 350 lbs./lane mi.2. Speed of truck spreading = 20 to 25 mph.3. Speed of truck not spreading = 35 to 40 mph.4. Capacity of Trucks:

A. 2 ½ Ton = 4.25 ton of material, adjusted to 90% of capacity toequal 22 lane mile spread;

B. 6 Ton = 7 ton of material, adjusted to 90% of capacity to equal 36lane mile spread;

C. 10 Ton = 12 ton of material. Adjusted to 90% of capacity to equal62 lane mile spread.

5. The initial spread to be accomplished within 1 ½ hours.

Once these constants were set, it was determined to find a relationship betweencenter line miles and lane miles.

To obtain this, three theoretical sections were established:

1. A two lane highway, 18 miles long;2. A four lane divided highway, 9 miles long;3. A six lane divided highway, 6 miles long.

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A 6-ton truck having a spreading capability of 36 lane miles was to spread eachsection three times and then the times would be compared. For this exercise, thefollowing constants were used:

1. Truck speed = 24 mph with spreading;2. Truck speed = 36 mph when traveling;3. Section begins as the Maintenance Yard;4. Loading time = ½ hour;5. Turn around time at the end of section = ¼ hour.

The time taken to completely spread each section three times was as follows:

(A) 6 miles @ 6 lanes = 3 hours, 15 minutes(B) 9 miles @ 4 lanes = 4 hours(C) 18 miles @ 2 lanes = 4 hours, 45 minutes

From the above, we found that it took approximately 20% longer to spread (B)above than (A) and about the same to spread (C) than (B). Section (B) is the averagehighway in New Jersey, based on the system of having 2,273.1 center line miles and9,201.8 lane miles (excluding ramp miles). Therefore, one center line mile equales 4.05lane miles.

From this data and through trial and error, the following was developed based ona standard section being a four lane divided highway.

The lane miles spread = .4 times the center line miles plus.9 times the lane miles

Check: 36 lane miles = A (9) mile section of divided highway having 4 lanes

36 = .4 (9) + .9 (36) = 3.6 + 32.436 = 36

Another key factor in spreading is ramps and the “dead-head” time lost inspreading them. It was finally established that a ramp lane mile would have a factor of2.5 times a mainline lane mile.

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The following formula for spreading was established after taking intoconsideration all of the various factors.

Formula

S = .4C + .9 [L + 2.5R]

S = Adjusted Lane Miles SpreadC = Centerline MilesL = Roadway Lane MilesR = Ramp Lane Miles

The above formula was further modified to take into account the age of theexisting fleet. The equipment utilization data supplied indicated an average 80% up timefor our truck fleet. This formula is as follows:

(S’) = S times 1.25

Truck Requirements

T = S’ = Total of 2.5 Ton Trucks needed to spread (S’)2.5 22

T = S’ = Total of 6 Ton Trucks needed to spread (S’)6 36

T = S’ = Total of 10 Ton Trucks needed to spread (S’)10 62

To check validity, the formulas were applied to two existing Maintenance Crews,one 1320 (Semi-Rural) and 2130 (Metropolitan), and calculated as follows:

Example No. 1

Crew 1320 C = 27.7 L = 95.2 R = 0

S = .4 (27.7) + .9 [95.2 + 2.5 (0)]S = 11.08 + 85.68 = 96.76 adjusted lane miles spreadS’ = 96.76 (1.25) = 120.95 = adjusted lane miles, including the equipment up time factor

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Truck Requirements

T = 120.95 = 5.5 = The total number of dump trucks required to man this section using2.5 22 only 2 ½ ton trucks.

T = 120.95 = 3.6 = The total number, if 6 ton trucks are used exclusively6 36

T = 120.95 = 2.0 = Trucks needed of using only 10 ton tandems10 62

Adjusted Mix of Trucks for Crew 1320

Since the bulk of New Jersey maintenance activities centers around the 2 ½ ton, 5 mancab, dump truck; the mix selected was:

T = (4) 4 trucks times 22 lane miles = 882.5

T = (1) 1 truck times 36 lane miles = 366

T = (0) 0 trucks times 62 lane miles = 010

5 trucks 120.95 < 124 lane miles

Example No. 2

Crew 2130 C = 16.6 L = 183.9 R = 23.0

S = .4 (16.6) + .9 [183.9 + 2.5 (23.0)]S = 223.90S’ = 223.9 (1.25) = 279.88

Truck Requirements – Adjusted Mix of Trucks for Crew 2130

T = 12.7 (4) 4 trucks times 22 lane miles = 882.5

T = 7.8 (4) 4 trucks times 36 lane miles =1446

T = 4.5 (1) 1 truck times 62 lane miles = 6210

9 Trucks 279.99 < 294 lane miles

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The above two Foreman’s sections were checked in the field for operationalfeasibility, and were found workable. In determining the mix of truck sizes needed, itrequires experienced judgment and knowledge of: year round maintenance workload,location of the maintenance yard to the foreman’s section and the lengths of varioushighways contained in the foreman’s section.

Loaders

Several time studies were taken under storm conditions and compared to ourexisting and past experience concerning how many trucks one loader could handle. Thiswas then translated into lane miles for a common base. The results were:

The number of loaders required equals the lane miles plus the ramp milesdivided by 150.

Number of Loaders Required = L + R150

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APPENDIX II

Plowing

The average annual snowfall in New Jersey varies from 14” in the southern areaof the State to 42” in the northwestern areas.

The spreading of deicing chemicals to have the highways in a wet condition is noteconomically feasible in storms of over 2”, and plowing is required.

The determination of when and how to plow is dependent on many variables, andjudgment by trained and experienced supervisors is essential. As a guideline – plows arerequired when 2” of snow has fallen, with a forecast of additional snow and/or droppingtemperatures.

In an effort to standardize plowing operations within the State, consideration ofthe many variables involved in plowing – including pavement width, shoulder width,number and complexity of ramp and interchange areas, speed of plow truck, size andangle setting of plow, rate of snow fall, general weather conditions, traffic density, timeof day, and experience of truck driver – led to the development of the following formula:

P = L + E + 2.5R7.5t

Legend: P = Number of plows requiredL = Lane miles of pavementE = Lane miles of shoulders over 5’ wideR = Lane miles of rampsT = Time in hours of one complete pass

The constant (7.5) in the denominator of the plowing formula represents theeffective width of plows in tandem. The rationale used to develop this constant is asfollows:

1. Pavement lane widths range from 10 to 13 feet and shoulders from 5 to 12feet. The average being 11 and 8 feet respectively. New Jersey’s averagehighway is four lanes with two shoulders; therefore, the width to beplowed in one direction is 30 feet (2 times 11 plus 8).

2. The typical plow used in New Jersey varies from 10 to 12 feet in length.Therefore, an average of 11 feet was used for the standard. When the 11-foot plow is placed at a 35 degree angle, it has the effective plowing widthof 9 feet.

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3. Due to heavy traffic densities on most New Jersey Highways, tandemplowing is required to minimize the effects of windrows of snow on thepavement. Plow overlap for tandem plowing is approximately 2 feet.

4. Normally, it is the policy to accomplish full-width plowing, includingshoulders, in one pass, because of the numerous driveways and streetinterchanges present on land service roads.

5. Using the information contained in 1 through 4 we find that:

a. First truck plows 9’ of the 30’, leaving 21’b. Second truck plows 7’ (9’ minus 2’ overlay) of the 21’, leaving 14’c. Third truck plows 7’, leaving 7’d. Fourth truck plows the final 7’

Therefore, 30 feet divided by 4 trucks equals (the constant) 7.5 feet of plowedwidth/truck.

Plowing speed is dependent on the type of pavement and highway design. Onfreeways and interstate speeds of 15-20 mph are expected while on land-servicehighways, 10-15 mph is more appropriate.

The effort of wider pavement and higher plowing speeds on freeways comparedwith narrower pavement and slower speeds on other roadways nearly balance out thesevariables.

Ramps are considered separately due to the “dead-heading” and slow down of theoperation and were assigned a factor of 2.5.

If time (t) equals two hours (practical for New Jersey’s plowing operations), theplow trucks required for crew 2130 can be calculated.

Example

Crew 2130

L = 183.9 lane miles (main pavement)E = 43.7 shoulder milesR = 23.0 lane miles (ramps)

P = L + E + 2.5R = 183.9 + 43.7 + 2.5 (23)7.5t 7.5 (2)

P = 19 trucks required for plowing

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Previously it was determined that Crew 2130 needed 9 trucks for spreading,therefore, Crew 2130 would need 10 additional trucks to meet the plowing requirements.

As in the example, and in most instances, it becomes very evident that the fleet oftrucks required for plowing operations is almost double the fleet required for chemicalspreading operations. Since it is not economically feasible to provide a State owned fleetof trucks to handle these emergencies, the formula provides an efficient and reliable toolfor determining the number of private contractor trucks that may be needed.

By setting the time to complete one pass (t) at two hours, the number of plowsrequired for Statewide or Regional operations can be calculated with the use of thephysical inventory. Should the required number of plows be reduced due to breakdowns,unavailability or other reasons, the time to make one complete pass (t) will increaseproportionally.

On a local or foreman basis, the formula enables the proper limits of a section tobe set, consistent with the rationale established; inasmuch as the number of plows intandem is fixed by ½ the total paved width; i.e.,

A 4 lane divided highway with shoulders – 4 plows are required.A 6 lane divided highway with shoulders – 6 plows are required.A 2 lane undivided highway with shoulders – 3 plows are required.

Typical plowing operations are as shown on attached sketches.

In addition, it is recognized that large, special “V” type plows, wing plows, androtary snow blowers are needed in certain instances during severe storms or in high driftareas. Such special equipment should be in addition to the basic plow fleet.

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APPENDIX III

Personnel Requirements

Personnel requirements are based on one man to a truck on a twelve hourrotational shift basis. Taken into account is benefit time and attrition, because turn ovenof employees is a way of life in Maintenance and should be recognized as such.

Fiscal year figures for 1976 were used for both the benefit time and the attritionrate.

Formula

(M) = (A) + (B) + (W)

M = Employees requiredA = Personnel required to man the spreading vehicles based on the

adjusted spread (S) plus loader operators. (The personnel is multipliedby 2 for 24-hour coverage.)

B = The benefit time which is 20% x (A)W = The attrition which is 8% x (A)

Since it is not economical to provide a fleet of trucks to cover plowing operations,personnel is based on spreading requirements. Exceptions to this rule would be forsections such as High Point, New Jersey, where historically, private contractors are notavailable. In these cases, the trucks required for plowing determine the personnel needs.It should also be noted that down time for the truck is not considered because personnelwill only be required for trucks in operating condition.

Example

Crew 2130

Trucks required for spreading (S) = 7 = 7 menLoaders required = 2 = 2 men

9 men/12 hour shift

A = 18 men for 24 hour dutyM = 18 + 0.2 (18) + 0.08 (18)M = 23 men

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APPENDIX IV

Equipment

Based on the spreading formula with adjustments for conditions within theregions, the number and size of dump trucks were calculated for each region. Therequired numbers of trucks for each region are:

Region 1 2 3 4 Total

2 ½ Ton Dump 81 61 113 100 3556 Ton Dump 41 37 53 29 16010 Ton Dump 7 4 6 3 20

Note: The number of 2 ½ ton and 6 ton dump trucks is based on 80% availabilityand 100% availability of 10 ton dump trucks.

The current distribution of the dump truck fleet is:

Region 1 2 3 4 Total

2 ½ Ton Dump 69 52 116 100 3376 Ton Dump 39 32 33 24 12810 Ton Dump 4 1 3 3 11

This shows that the following additional trucks are required in order to providethe service level demanded:

Region 1 2 3 4 Total

2 ½ Ton Dump 12 9 -3 0 186 Ton Dump 2 5 20 5 3210 Ton Dump 3 3 3 0 9

To reduce this deficiency, the following steps were taken:

1. The eighteen additional 2 ½ ton dump trucks are being obtained by crosstrading light graders for trucks being purchased with FY 1977 monies.This is possible due to the reduced demand for graders on maintenanceprojects. The regions have reviewed their needs for light graders andRegion 1 needs five, Region 2 needs one, Region 3 needs nine and Region4 needs four.

2. The shortage of 32 trucks in the 6 ton dump truck fleet is being made up,in part, by cross trading two rollers and three light graders. Plus, the

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purchasing of twenty additional 6-ton dump trucks with FY 1978 monies,made possible by the transfer of funds from the Bureau of Maintenanceaccounts to the Bureau of Equipment additional equipment account. Thiswill leave the 6-ton dump truck fleet seven trucks short of the numberneeded.

3. The shortage of 10-ton dump trucks is being eliminated by cross tradingsnow fighter trucks. In doing this, the Department is getting a vehicle thatcan be used year round.

In studying the age distribution of the dump truck fleet, it was found that for agiven age, each region did not have a proportional share of the trucks. But the averageage of the dump truck fleets in each region were approximately the same. It was agreedon not to move the trucks around so each region has its proportional share of each agegroup; but, to distribute new trucks based on the region percent of the fleet and makeadjustments on the older trucks, as needed when new truck orders are received.

The fleet percentages for each truck size are:

Region 1 2 3 4

2 ½ Ton Dump 23% 17% 32% 28%6 Ton Dump 24% 24% 32% 20%10 Ton Dump 35% 20% 30% 15%

Based on the above percentages, the dump truck orders for FY 1977 and 1978will change the fleet distribution as the following charts show;

Chart 1 (2 ½ Ton Dump Truck Status After First Order)

2 ½ Ton Dump trucks assigned by year, after the delivery of 96 trucks, includingcross-trading 18 small graders:

Region

Year Fleet 1 2 3 4

68* 29 9 15 0 570 56 15 11 23 771 78 19 10 28 2172** 7 0 0 0 774 36 5 3 9 1976 16 3 4 7 277 37 8 2 15 1278 96 22 16 31 27

355 81 61 113 100

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* Of the 17 – 1968 trucks traded in by Region3 (8) and Region 4 (9), 8 must bereassigned to Region 1 (2) and Region 2 (6).

** Also, three 1972 trucks from Region 3 must be reassigned to Region 1, asagreed on, to bring Region 1 and 3 in line with their spreading requirements.

Chart 2 (2 ½ Ton Dump Truck After Second Order)

2 ½ Tom Dump Trucks assigned by year, after the delivery of 70 trucks beingordered in Fiscal Year 1978:

Region

Year Fleet 1 2 3 4

70 15 8 6 1 071* 78 19 18 28 1372 7 0 0 0 774 36 5 3 9 1976 16 3 4 7 277 37 8 2 15 1278 96 22 16 31 2779 70 16 12 22 20

355 81 61 113 100

8 1971 Dump Trucks will be assigned to Region 2 from Region 4

Chart 3 (6 Ton Dump Truck Status After First Order)

6-Ton Dump Trucks assigned by year, after the delivery of 25 trucks, includingcross-trading 3 graders and two rollers (TD-1814 & TD-1816):

Region

Year Fleet 1 2 3 4

68 12 5 1 5 170 16 7 3 3 371 20 6 5 6 372 11 1 1 5 474 23 8 9 5 175 11 2 3 3 3

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76 8 2 1 2 377 7 2 3 1 178 25 6 6 8 5

133 39 32 38 24

Chart 4 (6-Ton Dump Truck Status After Second Order)

Region

Year Fleet 1 2 3 4

70 8 7 0 1 071* 20 6 4 7 372 11 1 1 5 474 23 8 9 5 175 11 2 3 3 376 8 2 1 2 377 7 2 3 1 178 25 6 6 8 579 20 5 5 6 4

133 39 32 38 24

*1 1971 from Region 2 to Region 3

Chart 5 (6-Ton Dump Truck Status After Third Order)

6-Ton Dump Trucks assigned by year, after the delivery of 20 trucks ordered inFiscal Year 1978 on the additional account:

Region

Year Fleet 1 2 3 4

70* 8 3 0 5 071** 20 6 2 10 272 11 1 1 5 474 23 8 9 5 175 11 2 3 3 376 8 2 1 2 377 7 2 3 1 178 25 6 6 8 579 40 10 10 12 8

153 40 35 51 27

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*4 – 1970 from Region 2 to Region 3**2 – 1971 from Region 2 to Region 3

***1 – 1971 from Region 4 to Region 3

NOTE: Seven more trucks will be needed to meet present 6-ton dumptruck requirements. (One in Region 1 and two in Region 2, 3, and4.

Chart 6 (10-ton Dump Truck Status After Ordering

10-ton Dump Trucks assigned by year after the delivery of 9 trucks ordered inFiscal Year 1978:

Region

Year Fleet 1 2 3 4

70 4 2 0 1 176 7 2 1 2 277 9 3 3 3 0

20 7 4 6 3

NOTE: Trading in TD-5878 FWD 10-ton dump truck and 8 snow fighters.