Maximum distance for reversing in Post Trip mode in metres. According to the specification referenced in Appendix A-1, index [C]. In https://www.era.europa.eu/sites/default/files/filesystem/ertms/ccs_tsi_annex_a_-_mandatory_specifications/set_of_specifications_3_etcs_b3_r2_gsm-r_b1/index004_-_subset-026_v360.zip Subset 26, chapter 7. 7.5.1.16 D_NVPOTRP.