Partial amendments  of the “Safety Regulation s for Road Transport Vehicle” , 
 the “Public Notice  that prescribes Details of Safety Regulations  
for Road Transport Vehicle”, and others  
 
April 2013  
Road Transport Bureau, MLIT  
 
1．Background  of the Amendments   
The Government of Japan  has implement ed regulations of exhaust emissions from 
motor vehicles in order to improve air quality  and introduced tighter regulation in  a 
step-by-step manner , consider ing situations such as air pollution , technological 
development  and relative global trends. Since  2011, Japan has increased emission 
regulation f or diesel heavy -duty vehicle s by introduc ing the high level  emission 
standards.  
Furthermore, t he Central Environment Council made the report as “Future Policy 
for Motor Vehicle Emission Reduction (9th report) ” in January 2008 and it also 
made the 11th report in August 2012 , both of which recommend increasing the 
emission regulation for diesel -power ed heavy -duty special  vehicle s and 
diesel -powered light -duty special vehicle s (hereinafter, referred to as  
“diesel -powered special motor vehicles ”) as follows:   
a) To introduce tighter emission standards on Nitrogen Oxide s (NOx)  
b) To require  measure s for blow -by gas  
c) To introduc e the Ramped Modal Cycle (RMC) provided in the new 
Non-Road Mobile Machinery global technical regulation  (NRMM gtr)  
developed  at the World Forum for Harmonization of Vehicle Regulations of 
the United Nations Economic Commission  for Europe  (UNECE/WP .29)  
d) To change the measur ing method of particulate matter  (PM) from the black 
smoke method to the method based on the light absorption coefficient . 
 
Based on the recommendation s above by the Central Environment Council, the 
Ministry of Land, Infrastructure, Transport and Tourism ( MLIT ) will partially 
amend the “Safety Regulation for Road Transport Vehicle ” (Ordinance  of the 
Ministry of Transport , No. 67 of 1952 ; hereinafter referred to as the “Safety 
Regulation” ） and the “Public Notice  that Prescribes Details of Safety Regulations 
for Road Transport Veh icle” (Public Notice  of MLIT , No. 619 of 2002 ; hereinafter 
referred to as the “Public Notice that Prescribes Details ”) in order to introduce 
tighter regulation of exhaust emissions from diesel -powered special motor vehicles . 
 
 2．Outline  of the Amendment   
 (1) Blow -by Gas Reducing Device  (Article 31 of the Safety Regulation, Article s 41,  
119 and 197 of the Public Notice that Prescribes Details ) 
[Scope ] 
Diesel -powered special motor vehicles with an engine that its rated output is of 
19kW or more but less than 560kW  
[Outline of the Amendment ] 
・ Installation of a device  to bring back  gas leaked from a combustion chamber of the 
engine to a crankcase , which, which is hereinafter referred  to as  “a blow -by gas 
reducing device” , shall be required . 
・ For the case that it is difficult to install a blow-by gas reducing device , it will be 
regarded as compliant provided that the amount  of the emission gas combined with 
blow-by gas , measured by the emission gas test (see Reference 1), meet the 
emission standards.  
 
(2) Introduction of a new test method for emission gas and of strengthened emission 
standards (Article s 41, 119 and 197 of the Public Notice that Prescribes Details )   
[Scope ] 
  Diesel -powered special motor vehicles with an engine that its rated output is of 
19kW or more ( as for strengthened emission standards for NOx , 56kW or more ) but 
less than 560kW  
[Outline of the Amendment ] 
・ RMC (see Reference  2) shall be introduced as the alternative  of C1 mode method 
for the emission gas test . 
・ Emission standards for NOx shall be increased for the e mission gas test.  （See 
Reference 3 ） 
 
(3) Introduction of a new measuring method for measurement of  PM (Article s 41, 119 
and 197 of the Public Notice that Prescribes Details ) 
[Scope ] 
  Diesel -powered special motor vehicles with an engine  that its rated output is  of 
19kW or more but less than 560kW  
[Outline of the Amendment ] 
・ As the measur ing method for PM, the “Measuring method of light absorption 
coefficient on black smoke at non -load rapid acceleration” ( Addendum 109 of the 
Public Notice that Prescribes Details)  shall be introduced in  place  of the method 
provided  in “Measuring method of black smoke at non -load rapid acceleration” 
(Addendum 46 of the Public Notice that Prescribes Details ), and the emission 
standard for black smoke shall be set as 0.5m-1.  
 (4) Others  
  In accordance with the amendments above , the “Public Notice that Provides 
Matters Necessary for Application of Provisions in Chapter 2 and 3 of  Safety 
Regulation for Road Transport Vehicles ” (Public Notice of MLIT , No. 1318 of 2003) 
will be amended, as appropriate.  
 
3．Date  of Entry  into Force   
   The date of entry into force will be set as follow s, depending on the types of  
Diesel -powered special motor vehicles : 
 
(1) New Type Approval Vehicle s 
Types of Vehicles  Date of entry into force  
Vehicle s with an engine that its rated output is of 19kW 
or more  but less than 56kW.  1 October 2016  
Vehicle s with an engine that its rated output  is of 56kW 
or more  but less than 130kW.  1 October 2015  
Vehicle s with an engine that its rated output is of 130kW 
or more  but less than 560kW.  1 October 2014  
 
 (2) Other than above mentioned    
Types of Vehicles  Date of entry into force  
Vehicle s with an engine that its rated output is of 19kW 
or more ( as for strengthened emission standards for NOx, 
56kW or more , as described  in 2. (2)) but less than 
130kW.   1 September 2017  
Vehicle s with an engine that its rated output is of 130kW 
or more  but less than 56 0kW. 1 September 2016  
 
4．Planned  Schedule   
・Date of Publication: June 2013 (tentative ) 
・Entry into Force: June 2013 (tentative;  simultaneously with the publication)  Reference 1: Example of the Measur ing method of Blow -by Gas based on NRMM gtr  
(A case to measure the blow -by gas mix ing with the tail pipe gas)  
 
(c) The laboratory crankcase exhaust tubing shall meet the engine manufacturer's specifications for 
crankcase back pressure;  
(d) The crankcase exhaust tubing shall connect into the raw exhaust downstream of any 
aftertreatment system, downstream of any installed exhaust restriction, and sufficiently upstream 
of any sample probes to ensure complete mix ing with the engine's exhaust before sampling. The 
crankcase exhaust tube shall extend into the free stream of exhaust to avoid boundary -layer effects 
and to promote mixing. The crankcase exhaust tube's outlet may orient in any direction relative to 
the ra w exhaust flow.   
(Cited from NRMM -gtr (ECE/TRANS/180/Add.11) 6.10.)  
 
 
(a) The tubing materials shall be smooth -walled, electrically conductive, and not reactive with 
crankcase emissions. Tube lengths shall be minimized as far as possible;   
(b) The number  of bends in the laboratory crankcase tubing shall be minimized, and the radius 
of any unavoidable bend shall be maximized;  
    (Cited from NRMM -gtr (ECE/TRANS/180/Add.11) 6.10.)  
 
Reference  2: C1 mode and RMC  
 
(1) About Ramped Modal Cycle  (RMC ) 
・ RMC is one of  steady state t ests cycles provided in  NRMM gtr . The cycles  are 
carried out under warm -start condition s similar to  C1 mode.  
・ Transition s between each mode shall be done within 20±1 seconds as linear shift s. 
・ Regarding a measurement of the e xhaust volume , it shall be measured by the same 
method as Non Road Transient Cycle ( NRTC ) and take samples continuously 
during the test cycle.   
 
 
(2) Comparison between C1 and RMC  
 
C1 mode  
 
Figures in table show WF [%].  
  RMC  
Figures in table show  time -ratio [%] 
toward total length of testing time.  
(Note: Mode transition time (8%) is 
eliminated .) 
Torque[%]  
Reference  3: Comp arison of the C urrent Emission Standards  and the ones to be 
amend ed 
 
Comparison Table on Emission Standards  for Diesel -powered special motor vehicles . 
Rated Output  CO NMHC  NOx  PM Diesel Black Smoke  
Current  Amend
ment  Current  Amend
ment  Current  Amend
ment  Current  Amend
ment  Current  Amend  
ment  
19kW  or more  
but less than 
37kw  
5.0 
(6.5)  
←  
0.7 
(0.9)  
←  
4.0 
(5.3) 
  
←  
0.03 
(0.04)   
←  
25% 
  
0.5m-1 
 
37kW  or more  
but less than 
56kW   
5.0 
(6.5)  
←  
0.7 
(0.9)  
←  
4.0 
(5.3)  
←  
0.025  
(0.033)   
←  
25% 
  
0.5m-1 
 
56kW  or more  
but less than 
75kW   
5.0 
(6.5)  
←  
0.19 
(0.25)   
←  
3.3 
(4.4)  
0.4 
(0.53)  
  
0.02 
(0.03)   
←  
25% 
  
0.5m-1 
 
75kW  or more  
but less than  
130kW   
5.0 
(6.5)  
←  
0.19 
(0.25)   
←  
3.3 
(4.4)  
0.4 
(0.53)  
  
0.02 
(0.03)   
←  
25% 
  
0.5m-1 
 
130kW  or 
more  but less 
than 560kW   
3.5 
(4.6)  
←  
0.19 
(0.25
)  
←  
2.0 
(2.7)  
0.4 
(0.53)  
  
0.02 
(0.03)   
←  
25% 
  
0.5m-1 
 
Note;  
1. Values in the column of  the “current ” and the “ amendment ” indicate mean values, and those  in “()” mean the upper limits.   
2. Values for CO, NMHC , NOx  and PM in the above table are shown in units of  g/kWh . 
3. Regulatory standards for  CO, NMHC , NOx  and PM are the values based on the measure ment  by 8 mode method, or RMC 
and NRTC mode method.   
4. Regulat ory standards for d iesel black smoke in the current regulation are  the value s based on the  measuring method of black 
smoke at non -load rapid acceleration with the use of black smoke  instrument . Those in the amendment are the values based on 
the measurement with Opacimeter.