[Code of Federal Regulations]
[Title 49, Volume 4]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR236.308]

[Page 498]
 
                        TITLE 49--TRANSPORTATION
 
       CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF 
                             TRANSPORTATION
 
 PART 236--RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND 
APPLIANCES--Table of Contents
 
                         Subpart C--Interlocking
 
Sec. 236.308  Mechanical or electric locking or electric circuits; requisites.

    Mechanical or electric locking or electric circuits shall be 
installed to prevent signals from displaying aspects which permit 
conflicting movements except that opposing signals may display an aspect 
indicating proceed at restricted speed at the same time on a track used 
for switching movements only, by one train at a time. Manual 
interlocking in service as of the date of this part at which opposing 
signals on the same track are permitted simultaneously to display 
aspects authorizing conflicting movements when interlocking is 
unattended, may be continued, provided that simultaneous train movements 
in opposite directions on the same track between stations on either side 
of the interlocking are not permitted.

    Note: Relief from the requirement of this section will be granted 
upon an adequate showing by an individual carrier to allow opposing 
signals on the same track simultaneously to display aspects to proceed 
through an interlocking which is unattended, provided that train 
movements in opposite directions on the same track between stations on 
either site of the interlocking are not permitted at the same time.