# Commission Delegated Regulation (EU) 2015/68 of 15 October 2014 supplementing Regulation (EU) No 167/2013 of the European Parliament and of the Council with regard to vehicle braking requirements for the approval of agricultural and forestry vehicles (Text with EEA relevance), Division 2.2.3.4

Extent: E+W+S+N.I.

With the exception of cases according to points 2.2.3.5 and 2.2.3.6, it is necessary for the determination of the braking rate of the towed vehicle to measure the braking rate of the tractor plus the towed vehicle and the thrust on the coupling. The tractor shall meet the requirements laid down in Appendix 1 with regard to the relation between the ratio TM/FM and the pressure pm,
where:
TM sum of braking forces at the periphery of all wheels of tractors
FM total normal static reaction of road surface on wheels of tractors
pm pressure at coupling head of control line
The braking rate of the towed vehicle shall be calculated according to the following formula:
zR = zR + M + D/FR
Where:
zR braking rate of the towed vehicle
zR + M braking rate of the tractor plus the towed vehicle
D thrust on the coupling (tractive force D > 0; compressive force D < 0)
FR total normal static reaction of road surface on all wheels of towed vehicle

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Source: https://www.legislation.gov.uk/eur/2015/68/annex/II/division/2/division/2.2/division/2.2.3/division/2.2.3.4 (the official version)
Page: https://openlegislation.uk/eu-regulation-2015-68/annex-II/division-2/division-2.2/division-2.2.3/division-2.2.3.4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.