Estimating Annual Waste Tire Generation, Diversion and Disposal in California A study for the California Integrated Waste Management Board Shawn Blosser

Estimating Annual Waste Tire

Generation, Diversion and Disposal in California

A study for the California Integrated Waste

Management Board

Shawn BlosserMatthew Newman

Trisha McMahonRob Wassmer

Presented By:

Building A Model

Review of Estimation Methods in Use Evaluation of Competing Methods Model Overview Data and Parameters Used Results Diversion & Disposal

Review Evaluation Model Data Results Diversion

Estimating States

Contacted all other 49 states

# States

States With Waste Tire Generation Estimates 37

States Without Waste Tire Generation Estimates 12

Total 49

Alabama, Delaware, Massachusetts, and Wisconsin do not track waste tire generation but are aware of the one tire per person per year metric. These states are reflected in the "states without waste tire generation estimates" category.


Per Capita Standard is Widespread

Over half used standard of 1 tire per person

# States

States Using Unknown Methodologies 2States Using 1 Tire/Person/Year 23

States Using Other Methodologies 12Total 37

Missouri and Nevada are counted in other methodologies even though they compare to 1 tire per person


Maryland, Vermont, and Wyoming methodologies may represent the use of one tire per person per year. Additional detail on these methodologies could not be obtained.

Three Other Methods In Use

New tire sales, waste tires received, state models

Methodology # States State(s)

Track Revenues Collected on Tire Sales 4 MO, NV, OK, VA

Track Waste Tires Collected 5 AZ, HI, NC, OH, TN

Industry Survey 1 SC

State-Created Model Estimate 2 FL, WA

Total 12

Oklahoma appears in track revenues, but it also tracks waste collected.


Basis of Per Capita Metrics

Rubber Manufacturers Association (RMA) standard of 1 tire per person

Replacement tire sales + Tires on scrapped vehicles = 299.5 million in 2005

299.5 million/ 296.4 million people

=1.01 PTEs per person/year Asked states to report waste tire generation:

299.15 million ≈ 1.01 PTEs per person/year.


Per Capita Metrics Are Underestimations

Does not account for variation in tire weights and sizes

Relies on self-fulfilling survey: 1 tire/person/year standard adopted by EPA At least 20 states use the metric as their sole

estimation methodology


Tracking Tire Fee Revenue Is Not Accurate

Underestimates: Captures just one of many flows of waste tires

net migration, internet sales, net imports, illegal tire sales, industrial waste

May not vary by tire size Oversimplifies:

Weights/sizes/characteristics of tires sold change over time

May not count government vehicles


Two States UseCustom Models

Existing models oversimplify: Florida model based on tire fees Washington based on vehicle registration

Do not account for other tire flows

Ignore the rate at which tires enter the waste stream


What Should A Model Do?

Fully incorporate all tire flows

Track tires over their lifespan

Account for variations in tire weights

Be flexible, state-specific, modifiable, and updatable


What Does Our Model Do?

1. Calculates the number of new tires sold in or entering the state every year

2. Assigns these tires to tire categories by weight

3. Estimates the length of time before they enter the waste stream

4. Tabulates the weight of these waste tires

5. Computes the results in PTEs and Tons


Passenger Vehicles

Autos, SUVs, Pick-ups, Vans,

Motorcycles

Light Trucks

Cargo trucks, 2-axle trucks, etc.

Medium Trucks

Semis & trailers

Heavy Trucks

Garbage trucks, etc.

Off-Road Vehicles

Construction and farm equipment

CA Tires“On the Road”Tires Entering CA Waste Tires

Re-Treading

Medium & Heavy Truck Tires Only

NEW TIRES

USED TIRES

Annual Industry

Sales Data(U.S.)

Breakdown of Estimated

Tires “on the road”for that year

Model estimates that

tires enter waste stream by category based on

either

(1) annual miles driven and tire life

expressed in miles, or

(2) industry estimates of

tire life expressed in

years

Waste Tires expressed in 20 lb. PTEs (Passenger Tire Equivalents)

Rubber waste

from re-treading

Avg. weight per tire calculated by category

using seller, manufacturer, or

industry standards. Passenger reflects CA registration in a year.

Assigned to Tire Categories

based on…Passenger Vehicles

Light Trucks

Medium Trucks

Heavy Trucks

Off-Road Vehicles

BOE Sales Data

New Tires Sales Not Included in

BOE Data

(Internet, etc.)

Net Population Migration from

Census


Overview of Model Parameters New Tires:

# of New Tires Sold: BOE Revenue # of Tires Sold on Internet: Modern Tire

Dealer # of Tires Sold to government entities:

Federal Highway Administration, CA registration stats.

# of Tires Brought in from Out-of-State: Net migration, # of people per HH, # of vehicles per HH

Tire Life: VMT for Passenger, Light Truck and

Medium Truck: Federal Highway Administration

Tread life for all types: National Highway Traffic Safety Administration

# of Retreads for all types: Tire Retread Information Bureau

Annual maximum life: Industry recommendations, RMA

Tire Allocations: # in Passenger, Light Truck, Medium

Truck, Heavy Truck, Off-Road: US Sales Distribution Statistics

Average Tire Weight: Passenger: Tire Size Sale Statistics,

Distributor Specifications, CA vehicle registration

Light Truck: Tire Size Sale Statistics, Distributor Specifications

Medium Truck: Manufacturer Specifications

Heavy Truck, Off-Road: Scrap Tire reports

% difference from new weight: CSUS survey, RMA, UK Environment Agency report.


Step 1: Calculate the Number of New Tires in CA

Our analysis shows that net imports, industrial waste, and illegal sales are insignificant sources of waste tires.

New tire sales in CANew tire sales from out-of-state Partially-used tires from net migration


2005 Tire Sale Distribution

Passenger78.45%

Light Truck13.28%

Medium Truck7.18%

Heavy Truck0.11%

Off-Road0.98%

Step 2: Assign New Tires to Categories

Passenger Vehicles Autos, Vans, SUVs, Pick-ups, Motorcycles P-metric tires

Light Trucks 2-axle, single-frame trucks with 6 or more

tires LT sized, smaller than 8.25” x 20”

Medium Trucks Semi-Trucks and Trailers, etc. Tires sized 8.25” x 20” to 11” x 24.5”

Heavy Trucks Garbage Trucks, etc. Tires sized 11” x 24.5” to 14” x 25”

Off-Road Vehicles Construction and Farm Equipment Tires sized 16” x 20.5” and larger,

plus farm equipment tires


Step 3: Estimate the Length of Time Tires are on the Road

Function of tire tread life, vehicle miles traveled (VMT), retreading, and time.

Tire CategoryTire Wear:

Tread Life / VMT

Time:

6 yearsRetread

Passenger Yes Yes* No

Light truck Yes Yes* No

Medium truck Yes Yes Yes

Heavy Truck No Yes Yes

Off Road No Yes Yes


*Tires wear out from use before 6 year limit is reached.

Step 4: Tabulate the Weight of a Scrap Tire

Calculated new tire weights for passenger, light truck, and medium truck tires Based on most popular tire sizes for passenger

and light truck, on popular brands for medium truck

Passenger average was weighted by registration data

Adjusted to reflect weight loss due to wear Estimated heavy and off-road tires based on

industry data


Step 5: Compute the Results

Follow tire cohort over the years

Estimate the number of tires that become waste each year

Sum waste tires

Divide by the Passenger Tire Equivalent (PTE)


Results

Average PTEs/person during 2005 – 2009: 1.24

Average total number of waste tires generated per year during 2005 - 2009: 46 million PTEs


Average PTE/Capita 2005-2009


Total Waste PTEs Generated (Millions)2005 2006 2007 2008 2009 TOTAL

Passenger Vehicles 24.02 24.19 21.68 24.20 27.34 121.43

Light Trucks 7.11 7.57 7.33 7.96 8.00 37.96

Medium Trucks 11.57 11.87 11.26 12.79 12.53 60.02

Heavy Trucks 0.25 0.24 0.26 0.26 0.29 1.29

Offroad Vehicles 1.85 1.93 1.99 1.98 1.97 9.72

TOTAL (MM) 44.80 45.81 42.51 47.19 50.12 230.43

Population (MM) 36.31 36.67 37.10 37.53 37.97 185.57

Per Capita PTEs 1.23 1.25 1.15 1.26 1.32 1.24

Per Capita Waste PTEs Generated

1.23 1.251.15

1.26 1.32

1.24

0.00

0.50

1.00

1.50

2005 2006 2007 2008 2009Per Capita PTEs 5-yr Avg: 1.24

Sources of Waste Tires


Average for 2005 to 2009 period.

Passenger Vehicles

53%

Offroad Vehicles

4%

Heavy Trucks1%

Light Trucks16%

Medium Trucks26%

The Variables that Drive Waste Estimates

Sales of new tires

Average weight of tires/percent lost to wear

Composition of vehicle fleet

Extent of retreading


Model Results Subject to Uncertainty

Range when average tire weight varies ±10%

Low: 1.12 Best: 1.24 High: 1.37


New Tire Weight: Top 10 Selling Passenger Vehicle Tire Sizes (2005)

0

20

40

60

80

100

120

140

160

0-15

16-1

717

-18

18-1

919

-20

20-2

121

-22

22-2

323

-24

24-2

525

-26

26-2

727

-28

28-2

929

-30

30-3

131

-32

32-3

333

-34

34-3

535

-36

36-3

737

-38

38-3

939

-40

40-4

141

-42

42-4

343

-44

44-4

545

-46

46-4

747

-48

48-4

949

-50

50+

New Tire Weight (lbs)

Nu

mb

er

of

Tir

e B

ran

ds

Original Equipment

Replacement

Wtd Avg New Tire Weight: 25.8 lbs.

Diversion & Disposal

2005 CIWMB estimate: 30.6 million diverted, 40.8 generated 75% diversion rate

Estimate segment of the market not included in survey Assume similar to those included with 75% diverted Use model generation estimate → 33.6 million diverted

RMA Estimates 67.99% diverted in CA National average rate is 86.6%


Documents

Estimating Annual Waste Tire Generation, Diversion and Disposal in California A study for the California Integrated Waste Management Board Shawn Blosser