Partial amendments of “Public No tice that Prescribes Details of  
Safety Regulations  for Roa d Transport Vehicle” , and others  
 
December 2017  
Road Transport Bureau, MLIT   
 
 1. Background  to the Amendments   
In September 2015, it was revealed that the manufacturer us ed defeat devices , 
which  activates the emission control system during the certification test  and 
deactivate the system  during real driving in the United States.  
In response to th is scandals , Japan  set "Working Group of Reviewing Diesel 
Passenger Vehicle Test Procedures for Addressing Defeat Device Scandal " by 
experts  in October 2015 , and, the working group has published  a final report to 
introduce the real driving emissions test  in April 2017.  
Following this report, in order to regulate the real driving emissions test Ministry 
of Land, Infrastructure, Transportation and Tourism( MLIT ) will amend Public 
Notice that Prescribes Details of Safety Regulations for Road Transport Vehicle  
(Public Notice of MLIT No. 619 on 2002)(hereinafter referred to as “Public Notice 
that Prescribes Details”) . 
In addition, MLIT  will make necessary amendments.  
 
2．Outline  of the Amendment   
(1) Develop of the test procedure for real driving emissions  (Public Notice that 
Prescribes Details, Article No.41)  
【Scope】 
1. A vehicle equipped with a compression ignition engine  with gross vehicle 
weight of 3.5t or less  
2. A passenger vehicle  with a compression ignition engine  for 9 or less passengers  
【Outline of the Am endment 】 
Develop  the real driving emissions test procedure referencing Euro6 -RDE  
The outline is as follows . 
 Measure emissions  when driving  on ordinary road and highway  using PEMS . 
 The test trip duration shall be between 90 and 120 minutes.  
 The distribution ratio of following speed range . 
Low speed (0 - 40km/h)    : 20 - 35% 
Middle speed (40 - 60km/h) : 30 ±10% 
High speed (60km/h -)     : 45±10% 
 The test shall be conducted between -2℃ to 38℃(the test result shall be 
divide d by 1.6  between  -2℃ and 0℃, and between 35℃ and 38℃) 
 The test shall be conducted at less than 1000m  altitude  (the test result shall 
be divide d by 1.6  at more than  700m)   
(2) Emission limit  
（Public Notice that Prescribes Details, Article No.41 ） 
【Scope】 
Same as (1)  
【Outline of the Amendment 】 
Emission limit for NOx has set double compared with the limit of laboratory 
testing.  
 
(3) Restrict the conditions to operate the protection strategy(*) , which may emit 
pollutant significantly （Public Notice that Prescribes Details, Article No.41） 
【Scope】 
Same as (1)  
【Outline of the Amendment 】 
Restrict the conditions to operate the protection strategy, which may emit 
pollutant significantly  as follow.  
(*) “protection strategy” means a emission control strategy which stops or 
reduces the effectiveness of the emission control system to protect the engine 
against damage or accident and to operate the vehicle safely.  
 The vehicle speed at 20km/h or less continues more than 20 minutes  
 The vehicle speed is more than maximum speed times 0.8, or the engine 
speed is more than peak power speed  
 The coolant temperature exceeds the boiling point minus 15 ℃ or 100℃ 
(whichever is higher)  
 Altitude is more than 1000m altitude.  
 Ambient temperature is -2℃ or below and 38 ℃ or more  
 The OBD detects any malfuncti on of emission control system and light up 
MIL.  
 
(4) Regarding amendments to (1) - (3), the  date of entry into force are following. 
(Public Notice that provides matters necessary for Application of provisions in 
Chapter 2 and 3 of Safety Regulation for Roa d Transport Vehicles (Public Notice 
of MLIT No. 1318 on 2003), Article No.28)  
 New Type Approval Vehicle : October 2022  
 Continuous Production Vehicle : October 2024.  
 
3．Schedule   
Scheduled for announcement  and enforcement  in late March 2018 .