Summary	of	Interagency	Working	Comments	on	Draft	Language	under	EO	

12866	and	EO	13563	Interagency	Review.		Subject	to	Further	Policy	Review.

Interagency	Comments	on	U.S.	Environmental	Protection	Agency	(EPA)	and	National	

Highway	Traffic	Safety	Administration	(NHTSA)	draft	proposed	rule	titled,	“Greenhouse	Gas	

Emissions	and	Fuel	Efficiency	Standards	for	Medium- and	Heavy-Duty	Engines	and	Vehicles	-

Phase	2.”		RIN	2060-AS16;	RIN	2127-AL52

Preamble

1. “Technology-forcing”	description

A. Is	there	a	legal	or	other	strong	reason	why	the	agencies	need	to	use	the	phrase	

“technology-forcing”	to	describe	the	fact	that	the	standard	will	drive	the	adoption	of	

innovative	technologies	that	are	not	yet	“off	the	shelf”? The	frequent	use	of	

“technology-forcing”	to	describe	the	standard	seems	to	unnecessarily	suggest	that	

the	agencies	are	forcing a	particular	technology	and,	additionally,	the	terminology	

has	an	inherent	negative	connotation	(as	if	the	standard	is	forcing	something	down	

industry’s	throat). If	a	particular	term	is	needed,	what	about	replacing	“technologyforcing”	with	something	more	neutral	and	accurately	descriptive	like	“technologyadvancing”	(which	is	used	in	the	brief	summary	at	the	start	of	the	preamble)?

B. Overall,	commenter	recommends	that	the	agencies	revisit	how	the	preamble	

describes	the	availability	of	fuel-saving	technologies	that	are	used	to	set	the	

standard. The	overarching	impression	from	the	summary	language	in	the	preamble	

is	that	the	standards	predominantly	rely	on	technologies	that	have	not	yet	been	

developed	or	demonstrated. If	it	is	true	that	most	of	the	reductions	are	achievable	

using	available/demonstrated	technologies	(as	seems	to	be	the	case)	– even	if	they	

have	not	yet	been	broadly/commercially	deployed	– that	is	an	important	point	to	

make	more	clearly	up	front	and	throughout	the	summaries	of	the	phase	2	

standards.

2. Credit	bank	size	– How	large	of	a	credit	bank	does	EPA/NHTSA	project	may	be	carried	over	

from	the	2014-2018	program	into	the	new	compliance	regime? Can	you	please	give	us	a	

sense	of	the	potential	size	range	of	this	credit	bank	in	order	to	evaluate	how	significantly	

the	carry-over	credits	may	impact	the	phase	2	program?	 EPA	notes	that	there	is	the	

potential	to	“accumulate	credit	surpluses	that	are	quite	large	at	the	beginning	of	the	

proposed	Phase	2	program.”	What	are	the	trade-offs	between	allowing	all	carry-over	of	the	

banked	credits	and	putting	some	type	of	credit	lifetime	(e.g.	5	years)	on	the	carry-over?		

3. Gasoline	vocational	engines – Can	the	agencies	provide	more	information	about	why	the	

absence	of	standards	for	gasoline	engines	for	vocational	trucks	won’t	create	a	significant	

incentive	for	operators	to	buy	(or	OEMs	to	produce)	gasoline	engines	instead	of	diesel	

engines?		What	are	the	differences	in	emissions	between	similar	size	gasoline	and	diesel	

vocational	trucks?

4. Low	GWP	refrigerants	– Is	EPA	considering	a	maximum	global	warming	potential	for	a	

“lower-GWP	alterative”	to	be	deemed	to	comply	with	the	HFC	leakage	standard,	as	

proposed	here?		EPA	is	about	to	issue	a	final	SNAP	rule	that	would	prevent	the	use	of	

certain	refrigerants	in	vehicle	AC	systems.		Is	OTAQ’s	analysis	based	on	what	would	be	

allowed	under	the	final	SNAP	rule	or	the	currently	permissible	set	of	approved	HFCs?
5. Emergency	Vehicles – What	is	the	share	of	emergency	vehicle	emissions	of	total	HDV	

emissions?	 What	is	the potential GHG	and	fuel	economy	impact	of	exempting	emergency	

vehicles	from	the	more	vocational	vehicle	standards?		Are	these	vehicles	exempted	because	

the	standards	may	interfere	with	their	performance	and	the	duties	for	which	these	vehicles	

are	employed (e.g.	fire	and	rescue,	disaster	relief,	law	enforcement)?

6. The	commenter	is	concerned	that	the	impacts	on	small	trailer	manufacturers	are	hard	to	

understand	because	of	the	aggregation	of	all	small	entities.		Commenter	suggests	a	breakout	

of	small	trailer	manufacturers	by	size	to	help	understand	the	relative	costs	of	regulatory	

compliance.		Could	EPA	breakout	in	a	table	the	distribution	of	small	business	trailer	

manufacturers	by	annual	sales?		Commenter	would	like	to	see	how	many	of	these	

businesses	have	less	than	$5	million	in	annual	sales.		Annual	sales	could	be	broken	down	in	

intervals	of	$5	million	from	$0	up	to	$65	million	(the	top	range	from	Ch.	12	of	the	RIA),	or	a	

similar	breakout	with	a	focus	on	what	the	low	end	of	the	distribution	looks	like.	This	will	

show	if	small	businesses	are	concentrated	anywhere	in	the	distribution,	and	provide	a	

better	understanding	of	the	economic	impact	the	estimated	compliance	costs	are	likely	to	

have	on	a	cost-to-sales	basis.

7. In	addition	to	delaying	implementation	for	small	businesses	for	a	year,	are	there	any	

incentives	we	can	provide	for	compliance?		Has	the	agency	considered	streamlined	the	

testing/certification	or	reporting/recordkeeping	requirements	for	small	businesses?

8. In	the	preamble,	please	consider	referencing	the	vehicle	fuel	savings	from	Phase	1	of	the	

program	so	that	the	public	understands	the	combined	total	savings	from	Phase	1	and	the	

proposed	Phase	II	programs.		

9. Are	there	statutory	or	other	limitations	for	the	compliance	timing	proposed	in	the	rule?		

Suggest	the	agency	take	comment	on Alternative	4.	(see	pg	131)	to	open	the	option	of	

moving	the	timeline	earlier	for	a	portion	of	the	technologies,	if	not	all	of	them,	and	

considering	the	feasibility	of	moving	up	the	compliance	period	up	1-2	years,	if	three years	is	

not	feasible.		Also	suggest	the	agency	take	comment	on	any	potential	cost	or	feasibility	

impacts	of	earlier	compliance	timing	considering	the	design,	certification,	and	other	

requirements	imposed	by	the	rule.		

10. In	the	RIA	(pg.	5-1),	consider	replacing	the	sentence	“According	to	the	IPCC,	anthropogenic	

emissions	of	GHGs	are	very	likely	(90	to	99	percent	probability)	the	cause	most	of	the	

observed	global	warming	over	the	last	50	years.”	with	EPA	and	NHTSA’s	regular	climate	

messaging.

11. Will	EPA/NHTSA	confirm	that	engines/equipment	used	in	underground mining	are	

excluded	if	they	are	regulated	by	the	Mine	Safety	and	Health	Administration?

12. We	suggest	EPA	conduct	a	mid-term	review	of	the	certification/testing	requirements,	

including	reviewing	the	need	to	collect	data	that	can	be	reliably	extrapolated.

13. We	suggest	EPA	conduct	a	retrospective	analysis	to	assess	the	adoption	rate	and	the	price	of	

the	vehicles.		We	suggest	that	this	should	be	done	before	the	Phase	2	of	the	rule	begins.

14. We	suggest	EPA	conduct	a	technical	mid-term	review	4-5	years	into	the	Phase	2.
15. Averaging,	banking,	and	trading	(ABT).	The	program	under	Phase	1	currently	allows	for	

many	compliance flexibilities	including	the	averaging,	banking,	or	trading	of	emissions	

credits.	 Through	these	flexibilities, manufacturers	are	allowed	to	carry-forward	credit	

deficits	for	up	to	three	model	years.	 As	the	regulations transition	from	Phase	1	to	Phase	2,	

the	Agencies	are	proposing	to	recognize	innovative	technologies	that were	not	accounted	

for	by	the	Phase	1	test	procedures.	 This	recognition	aims	to	further	incentivize

manufactures	to	develop	advanced	technologies	early	for	faster	compliance	and	to	further	

reduce	GHG emissions.	 The	Agencies	are	proposing	a	1.25	adjustment	factor	for	credits	

carried forward	from	Phase	1	to Phase	2,	but	with	no	analytical	support	for	how	the	1.25	

factor	was	determined.		Recommendation: Commenter	requests that	the	Agencies	perform	

this analysis or	point	to	where	it	has	already	been	done	in	the	agency	preamble,	RIA	or	

memo	to	the	docket.	 This	type	of	analysis	would	consider	various	adjustment	factor	levels,	

which	could	then	be	used	to	choose	the	adjustment	level as	it	is	not	clear	how	the	agency	

chose	1.25.		Would	this	adjustment factor	result	in	any discount	of	banked	credits	that	are	

carried	forward	from	Phase	1	to	Phase 2?

Are	the	agencies	allowing	for	ABT	across	all	categories of	vehicles?		Wouldn’t	allowing	ABT	

across	all	categories	increase	compliance	flexibilities	and	reduce	manufacturer	compliance	

costs?		What	concerns	would	the	agency	have	with	allowing	ABT	across	all	categories?		

16. Safety	concerns.	The	Agencies’	proposal	repeatedly	indicates	that	“the	rule	should	have	no	

adverse	impact on	vehicle	or	engine	safety,”	but	with	few	details	as	to	how	the	Agencies	

have	evaluated	whether implementing	of	the	rule	will	actually	adversely	affect	driver	safety.	

The	extent	of	any	safety	analysis	for trailers	is	essentially	described	by	noting	that	trailer	

manufacturers	will	continue	to	be	required	to	meet current	safety	regulations	for	the	

trailers	they	produce.	The	proposed	available	technologies	for	trailer compliance,	for	

instance,	include	tire	pressure	systems	and	recommended	psi	levels	that	will	lead	to

increased	fuel	efficiency.	Similarly,	available	technologies	also	include	empty	trailer	weight	

reduction	by replacing	steel	with	aluminum	or	lighter-weight	composites.	For	each	of	these	

proposed	technologies,	a feasibility	analysis	is	summarized	without	any	description	of	the	

safety	impacts.		Recommendation:	Request	further	discussion	on	the	potential	safety	effects	

of	the	proposed	suite	of	technologies	that	would	employed	to	comply	with	the	rule.	Each	

section where	the	Agencies	state	that	“there	will	be	no	impacts	on	safety”	should	include	a	

rational	as	to	how	the Agencies	came	to	this	conclusion.	The	Agencies	should	also	seek	

comment	on	the	safety	effects	of	proposed technologies.

17. Links	to	the	Renewable	Fuel	Standards.	 Does	this	proposal	include	a	discussion	of	the	

upstream	benefits	of	combusting	biofuels in	lieu	of	conventional	fuels?		The	draft	rule	does	

mention	that	the	“rulemaking	is	not	expected	to	impact	biofuel volumes	mandated	by	the	

Annual	Renewable	Fuel	Standards	regulations;”	however,	the	agencies	consider the	two	

rulemakings	distinct	and	do	not	discuss	how the	biofuels	markets	could	affect	the	proposed	

changes to	heavy	duty	vehicles. Recommendation:	A	discussion	and	analysis	of	biofuels	

would	help	explain	the	cumulative	regulatory	impact	of	this	rule	and	other	EPA	air	rules	

such	as	RFS.		

18. It	appears	that	the	rule	estimates	benefits	of	upstream	emissions	but	does	not	allow	

manufacturers	to	count	upstream	emissions	for	compliance	purposes,	please	confirm.		
Suggest	that	any	upstream	emissions,	such	as	methane	from	natural	gas	vehicles,	are	

counted	in	the	agency	cost/benefit	analysis.		Allowing manufacturers	to	count	upstream	

emissions	as	part	of	their	compliance	testing	to	account	for	the	full	environmental	impacts	

of	technologies.		

19. It	is	unclear	how	this	rule	will	affect	the	truck	manufacturing	markets,	considering	Free	

Trade Agreements	with	Mexico	and	Canada.	Is	there	a	concern	that	this	regulation	could	

cause	truck	assembly plants	or	sales	offices	to	move	to	outside	of	the	US,	(e.g.	to	sell	trucks	

to	Mexican	trucking	companies operating	in	the	US,	thereby	avoiding	the	fuel	economy	

standards)?	 The	Environment	Canada	section	(page 25)	discusses	working	on	a	joint	US—

Canada	approach,	with	a	goal	of	achieving “a	common	set	of	North American	standards.”	

However,	no	discussion	of	Mexico	is	included	in	this	proposal	with	no	consideration	to

Mexican	standards,	nor	trade/manufacturing	considerations.		The	commenter	requests	that	

the	agencies	include	a	discussion	of	any	potential	Mexican	standards	if	any	and	any	

interaction	with	Canadian	standards.

20. If	congress	chose	to	change	the	maximum	weight	limit	on	trucks,	or	as	states	consider	

exemptions	to limits	for	special	vehicles,	how	would	the	impacts	of	the	rule	change?	For	

example,	would	a	truck	be	able	to	haul 90,000	or	100,000	pounds	and	still	comply	with	the	

fuel	efficiency	standards?	Have	the	Agencies	considered higher	weight	limits	on	trucks?	

How	would	weight	changes	affect	GHG	and	safety	considerations?

21. Do	EPA/NHTSA	anticipate	that	the	will	affect	domestic	commodity	markets?	For	example,	

the	weight reduction	in trailers	may	affect	metal	producers.

22. Will	EPA/NHTSA	share	the	charge	questions	for the	computer	certification	system	(this	

model	is	also	out	for	public	comment)?	 We	have	not	seen	those circulated	yet	and	are	

interested	in	reviewing	them.

23. EPA/NHTSA,	please	be	sure	to	submit	your	information	collection	request	associated	with	

this	final	rule	prior	to	issuing	the	NOPR	in	the	federal	register.

24. Suggest	agencies	include	the	analytical	impacts	of	having	separate	engine	standards from	

the	full	vehicle	standards and	present	the	costs,	benefits,	and	net	benefits	with	and	without	

engine	standards.		Suggest	that	agencies seek	comment	on	whether	engine	standards	are	

necessary	for	the	final	rule	stage	and	on	the	reliability	of	the	emissions/fuel	economy	

estimates	for	the	remainder	of	the	vehicle.

25. Data	collection.	Compliance	with	the	EPA	and	NHTSA	standards	is	assessed	using	a	set	of	

simulation	models.	 Real-world	fuel	consumption	and	emissions	may	differ	from	the	

modeled	estimates	either	because	of	bias	inherent	to	the	models	themselves	or	because	of	

inaccurate	assumptions	about	duty	cycles	or	other	model	inputs.	 Because	so	little	data	are	

collected	on	the	actual	operation	of	the	regulated	trucks,	the	concern	here	is	not	about	any	

potential	bias	of	the	models	themselves,	but	rather	about	the	model	inputs.	In	particular,	

the	Vehicle	Inventory	and	Use	Survey	was	last	conducted	in	2002,	and	both	the	Phase	1 rule	

and	the	Phase	2	proposal	note	the	lack	of	high-quality	data	on	trucking.	 Although	the	

Agencies	have	done	an	admirable	job	in	conducting	outreach	with	the	industry,	and	

Smartway	collects	some	information	from	participants,	these	data	sources	do	not	substitute	
for	comprehensive	data	on	how	the	trucks	are	actually	used	in	the	real	world.	 We	suggest	

developing	a	plan	to	collect	representative	data	from	across	the	regulated	sectors.		We	also	

suggest	that	the	agency	use	this	data	to	conduct	a	mid-term	review,	somewhere	near	the	

mid-point	of	the	2018-2027	compliance	period,	to	consider	any	new	information	to	confirm	

or	update	agency	assumptions	and	standards.		
Regulatory	Impact	Analysis

26. Shouldn’t	the	annualized	cost	using	3%	discount	rate	be	different	than	annualized	cost	

using	7%	discount	rate	since	variable	costs	are	incurred	beyond	year	1	of	the	program	(ES2)

27. How	do	the	new	RPE	results	compare	with	previous	GHG	rules	(2-178,	2-180)?

28. EPA’s	assumption	about	market	forces	seems	to	be	inconsistent	with	respect	to	the	GEM	

regeneration	impact	on	fuel	consumption	(p.	3-2).		How	much	is	the	fuel	penalty	associated	

with	regeneration?	

29. The	current	discussion	on	the	emissions	test	engine	seems	to	suggest	that	the	agency	is	

testing	for	worst	performance	which	would	imply	that	the	firms	may	be	expected	to	“overcomply”	(p.	3-4).		Is	this	true?

30. Why	wasn’t	there	a	similar	presentation	of	the	Alternative	2	as	the	Alternative	4?

31. If	this	rule	has	the	potential	to	lower	world	oil	price	(p.	5-8),	why	wouldn’t	this	rule	have	

the	potential	to	affect	the	ethanol	market	(5-24)?

32. Why	is	the	loss	fraction	for	HFC134a	at	end	of	life	higher	than	leaks	and	servicing?		Isn’t	

there	an	anti-venting	requirement	already	in	place	for	equipment	at	end	of	life?

33. Is	the	Minnesota	database	(5-26)	of	sufficient	quality	to	be	extrapolated?

34. What	is	the	likely	source	of	NOx	and	SO2	reduction	due	to	this	rule	(6-43)?

35. Does	the	compliance	cost	include	land	acquisition	cost	associated	with	new	test	facilities	(7-

5)?

36. Why	are	the	fuel	expenditures	decreasing	relative	to	other	categories	in	Table	7-23	(7-21)?

37. Section	“7.2.1	Vehicle	Program	Costs”	appears	to	be	duplicative	of	EPA’s	analysis.		Is	this	

true?

38. How	did	EPA	estimate	the	non-CO2	GHG	reductions?		Where	are	the	reductions	presented?

39. Page	8- 58	the	first	sentence.	Was	this	not	answered	in	Phase	1?

40. Page	8-60.	Please	provide	more	details	and	clarity	regarding	the	calculations.	How	did	

agencies	get	these	calculations	and	numbers?

41. Page	8-60- did	the	agencies	mean	to	say	producer	surplus	instead	of	consumer	surplus?	

What	is	the	producer	surplus	per	mile?

42. Request	that	the	agencies	provide	a	breakout	of	the	costs	and	benefits	for	each	individual	

vehicle	category	as	opposed	to	just	aggregate	costs/benefits	so	that	the	impacts	of	each	

category	of	trucks is	clearly	stated	for	the	public.		

43. Baseline:		The	results	of	the	Section	“7.2.1	Changes	in	fuel	consumption	and	savings”	seems	

counter	intuitive	given	the	assumptions	of	use	of	credits	from	the	existing	HD	program	and	

more	adoption	of	fuel	saving	technologies	in	the	baseline.		We	request	a	briefing	on	this	

section.		We	request	that	EPA/DOT	explain	the	differences	between	the	less	dynamic	

baseline	vs	more	dynamic	baseline,	modeling	assumptions	between	EPA	and	DOT,	and	how	

these	differences	contribute	to	the	differences	in	the	results.
44. Chapter	7	of	the	RIA	presents	technology	cost	estimates	under	two	alternative	baseline	

assumptions. The	first	case	projects	improvements	in	trailers	in	the	absence	of	Phase	2,	but	

not	for	other	vehicles.	 The	second	case	projects	some	improvement	for	vehicles	other	than	

vocational	vehicles.	 The	second	“more	dynamic”	baseline	should	incorporate	estimated	

payback	periods	reported	in	the	literature,	such	as	the	focus	group-based	studies	by	EPA	

and	other	researchers.	Based	on	prior	meetings	with	the	agencies,	it	seems	that	in	the	more	

dynamic	baseline	it	is	assumed	that	any	technology	with	a	payback	of	6	months	or	less	is	

adopted	in	the	absence	of	Phase	2. The	6-month	criteria	tries	to	balance	the	observation	

that	technologies	have	been	adopted	steadily	in	the	past,	but	that	certain	factors,	such	as	

incomplete	information	or	uncertainty	about	technology	costs	or	performance,	delay	

adoption.	 It	is	great	that	the	agencies	are	considering	a	baseline	in	which	some	technology

is	adopted,	but	there	is	not	strong	support	for	a	criteria	of	6	months.	There	is	no	evidence	

that	firms	actually	use	6-month	payback	periods	when	evaluating	technologies.	For	

example,	the	NCEE	staff	working	paper,	which	was	based	on	focus	groups	and	interviews	

(i.e.,	not	a	representative	sample),	mentions	that	some	respondents	require	a	positive	

return	on	investment	within	18	months	to	3	years.	It	would	be	inappropriate	for	the	

agencies	to	begin	with	an	estimate	of	a	“typical”	industry-reported	payback	period	and	

adjust	that	estimate	downwards	for	reasons	like	uncertainty	or	incomplete/asymmetric	

information.	 That’s	inappropriate	because	the	payback	period	already	accounts	for	these	

factors;	further	adjusting	the	payback	period	towards	zero	would	be	double-counting	their	

influence	on	payback	periods.

45. Energy	efficiency	paradox.	Chapter	8	restates	from	the	phase	1	rule	five	potential	

explanations	of	the	energy	efficiency	paradox.	The	chapter	contains	an	extensive	discussion	

of	the	focus	group-based	studies	that	have	been	conducted	since	the	phase	1	rule.	It	is	

disappointing	that	the	agencies	cannot	provide	more	comprehensive	evidence	of	the	

existence	and	reasons	for	the	paradox.	The	focus	groups	studies,	while	being	rigorous	

themselves,	do	not	provide	a	representative	description	of	the	broad	range	of	trucks	being	

regulated;	the	studies	themselves	note	this	shortcoming.	Why	were	the	agencies	unable	to	

conduct	a	comprehensive	analysis	of	the	industry—or	at	least	covering	the	freight	sector	

given	its	relative	importance	in	overall	fuel	consumption—in	the	time	since	the	phase	1	

rule?	Could	they	conduct	such	an	analysis	in	time	for	the	final	Phase	2	rule?

46. In	addition,	the	discussion	of	the	energy	efficiency	paradox	should	clarify	that	information	

problems	or	the	length	of	time	for	technologies	to	become	available	are	not	themselves	

market	failures	that	justify	regulating	fuel	consumption	or	GHG	emissions.	If	there	is	

incomplete	information	about	the	performance	or	cost	of	a	technology,	regulating	its	use	

does	not	improve	welfare	if	market	participants	have	unbiased	beliefs	about	cost	or	

performance.	Likewise,	if	manufacturers	typically	take	time	to	introduce	new	technology,	

that	may	be	because	there	is	a	real	cost	of	accelerating	the	pace	at	which	they	offer	new	

technology—for	example,	it	may	take	time	to	sufficiently	test	a	new	technology	to	be	sure	

about	its	durability.	Regulations,	like	Phase	2,	that	speed	up	the	pace	at	which	the	

technology	is	offered	therefore	impose	real	costs	on	the	industry.	Presumably	these	costs	

are	properly	accounted	for	in	the	cost	analysis,	so	the	point	here	is	not	that	the	costs	are	

mis-estimated.	Rather,	the	point	is	that	a	perceived	slow	pace	of	offering	technology	does	

not	represent	a	market	failure	or	a	justification	for	regulation.	
47. Rebound.	The	discussion	of	the	rebound	effect	does	not	account	for	the	effect	of	the	rule	on	

the	management	of	multi-truck	fleets	and	on	competition	between	new	and	old	trucks	to	

provide	trucking	services.	Increasing	the	fuel	economy	of	new	trucks	would	cause	several	

types	of	changes	in	the	operation	of	new	and	older	trucks.	First,	multi-truck	fleet	operators	

may	shift	miles	traveled	to	their	new,	more	fuel	efficient	trucks,	and	away	from	their	older	

trucks.	Second,	operators	with	new	trucks	may	be	more	successful	at	bidding	for	contracts	

against	operators	with	older	trucks.	Third,	operators	with	new	trucks	may	compete	with	

other	transportation	modes.	All	three	responses	might	be	characterized	as	“rebound”	in	the	

sense	that	the	new	trucks	meeting	the	GHG/fuel	economy	standards	are	driven	more	miles	

than	would	new	trucks	in	the	absence	of	Phase	2.	But	the	first	two	responses	result	in	an	

overall	decrease in	fuel	consumption	and	GHG	emissions.	Accounting	for	them	would	

increase the	net	benefits	of	the	rule.	The	Phase	2	rule	should	distinguish	these	responses	

and,	ideally,	the	agencies	could	use	data	(e.g.,	from	SmartWay)	to	estimate	the	relative	

importance	of	the	three	responses.

Based	on	our	preliminary	review,	it	appears	that	the	analytical	values	used	to	estimate	the	

rebound	effect	are	not	consistent	with	what	is	supported	by	studies	and	evidence.	 Many	of	

the	rebound	effect	values	used	are	point	estimates	outside	of	the	ranges	suggested	by	

studies	cited	in	the	rule.	

48. Interactions	with	NAAQS.	The	RIA	quantifies	the	reductions	in	non-GHG	pollutants	such	as	

nitrogen	oxides	and	monetizes	the	resulting	health	benefits	from	improved	air	quality.	This	

is	fine	in	itself	but	it	should	be	noted	that	the	truck	rule,	if	finalized,	would	affect	the	

baseline	from	which	the	costs	and	benefits	of	future	NAAQS,	such	as	the	upcoming	ozone	

standards,	are	estimated.	That	is,	the	truck	rule	would	reduce	the	costs,	benefits,	and	net	

benefits	of	tightening	ozone	standards.	Presumably	the	EPA	will	adjust	the	baseline	in	the	

RIA	for	the	final	ozone	standards,	but	we	suggest	mentioning	this	implication	for	the	truck	

rule.		

Editorial

49. The	presentation	of	the	sea	level	effect	appears	to	be	weak	and	open	the	agency	to	potential	

ridicule	(6-45).		If	this	is	not	central	to	EPA’s	argument,	we	suggest	limiting	the	presentation	

to	CO2	concentration	and	the	temperature	implications.

50. We	suggest	replacing	“standard	discount	rates”	with	“discount	rates	used	in	this	analysis”	

(8-4).

51. We	suggest	updating	the	reference	list	to	include	all	the	source	materials	referenced	in	

Chapter	8.

52. We	suggest	deleting	the	discussion	on	p.	8-25.		This	discussion	doesn’t	seem	to	be	central	to	

the	rebound	discussion	and	is	very	confusing.

53. Would	EPA	send	over	a	copy	of	West	el	at	(2006)	(8-42)?

54. Please	revise	the	title	of	Table	8-40	to	articulate	that	it	only	includes	substitution	effect	(8-

91).

55. Please	provide	the	source	material	for	the	statement	that	the	fuel	suppliers	are	“materialintensive”	(8-92).
56. We	suggest	replacing	“substitution	effect	is	expected	to”	with	“substitution	effect	is	

associated	with	potential”	(8-93).

Suggested	Solicitations	for	Comment

57. Suggest	that	the	agencies	include	a	section	in	the	preamble	that	is	referenced	in	the	table	to	

contents	with	a	list	of	all	of	the	requests	for	comment	that	were	made	throughout	the	

preamble/RIA	documents.		It	will	be	helpful	to	the	public	to	have	all	of	these	requests	for	

comment	in	one	place	as	the	document	is	very	long.

58. Please	solicit	comment	on	the	type	of	technologies	and	the	expected	introduction	to	

commerce	of	those	technologies	that	EPA	assumes	will	take	place	in	the	RIA.

59. Please	solicit	comment	on	whether	there	are	other	barriers	to	adoption	of	fuel	efficient	

technologies	such	as	redundancies	(two	tires	vs	single	tire).

60. In	regards	to speed	reduction	as	a	fuel	saving	approach,	please	solicit	comment	on	whether	

additional	trucks	would	have	to	be	deployed.

61. Please	solicit	comment	on	the	indirect	cost	multipliers	used	in	the	RIA	(Table	2-86,	p.	2-

182).

62. Please	solicit	comment	on	the	learning	effects	applied	in	the	RIA	(Tables	2-89,	2-90).

63. Please	solicit	comment	on	the	technology	adoption	rates	used	in	the	RIA	(tables	presented	

from	p.	2-193	to	p.	2-259,	11-24	to	11-45).

64. Please	solicit	comment	on	all	aspects	of	testing	and	certification	requirements	that	deviate	

from	the	existing	requirements.

65. Please	solicit	comment	on	the	projected	truck	sales	and	the	truck	turnover	rate,	including	

the	potential	to	rebuild	existing	trucks.

66. Please	solicit	comment	on	the	projected	energy	rate	reduction	(Tables	5-21,	5-24)	or	

projected	achieved	fuel	consumption	reduction	(Tables	5-27,	5-29)	due	to	this	NPRM.

67. Please	solicit	comment	on	the	estimated	technology	costs	per	vehicles	(tables	7-1).

68. Please	solicit	comment	on	the	costs	associated	with	testing	and	certification	(7-5	– 7-6)	and	

R&D	(7-8).		The	tables	associated	with	these	discussions	seem	not	as	clear.

69. Please	clarify	what	maintenance	categories	are	included	in	Table	7-18	(7-17)	and	solicit	

comment	on	the	estimates	presented	in	the	table.