49 CFR § 236.512 - Cab signal indication when locomotive enters block where restrictive conditions obtain.

---
identifier: "/us/cfr/t49/s236.512"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 236.512 - Cab signal indication when locomotive enters block where restrictive conditions obtain."
title_number: 49
title_name: "Transportation"
section_number: "236.512"
section_name: "Cab signal indication when locomotive enters block where restrictive conditions obtain."
chapter_name: "FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
part_number: "236"
part_name: "RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 20102-20103, 20107, 20133, 20141, 20157, 20301-20303, 20306, 20501-20505, 20701-20703, 21301-21302, 21304; 28 U.S.C. 2461 note; and 49 CFR 1.89."
regulatory_source: "33 FR 19684, Dec. 25, 1968, unless otherwise noted."
cfr_part: "236"
---


# 236.512 Cab signal indication when locomotive enters block where restrictive conditions obtain.

The automatic cab signal system shall be arranged so that when a locomotive enters or is within a block, wherein any condition described in § 236.205 obtains, the cab signals shall indicate “Proceed at Restricted Speed.”