Dia. 652 illumination requirements https://members.theihe.org/forums/posts.aspx?group=214541&topic=1489159 Sun, 7 Jun 2026 22:21:54 GMT Thu, 23 May 2019 08:24:14 GMT Copyright © 2019 Institute of Highway Engineers Dia. 652 illumination requirements https://members.theihe.org/forums/posts.aspx?group=214541&topic=1489159 https://members.theihe.org/forums/posts.aspx?group=214541&topic=1489159
BrynBuck 
I presently have a looming maintenance time bomb in the form of a vast number of Dia. 652 signs which were installed in the 1970s and 1980s on standard CHS with no illumination. These obviously are not compliant with Schedule 17 of the current regulations.

My problem arises in that many of these CHS are Now corroded and the plates themselves are faded and would not meet any retroreflectivity standards.

A bulk replacement to introduce illuminated Dia. 652s would exceed the annual sign maintenance pot yet I am fairly certain there is little to no chance of obtaining a retrospective special direction from the Department as Schedule 17 is rather explicit on the issue of lighting signs.

A number of these signs are now within 20mph Zones but unless I have misinterpreted the draft Regs Dia. 652 will still need to be illuminated unless used as a repeater more than 50m away from a side road?

Any suggestions would be most welcome as I am receiving further requests for reviews of one way systems and I don't particularly wish to perpetuate something that may be wrong as if a special direction was issued it has since been lost in subsequent local government reorganisation.
]]> Thu, 23 May 2019 09:23:47 GMT https://members.theihe.org/forums/posts.aspx?group=214541&topic=1489160 https://members.theihe.org/forums/posts.aspx?group=214541&topic=1489160 March 2015

Hi Bryn

In the current (2002) TSRGD 652 only has to be electrically lit if it needs to be seen by drivers who have just turned into that road within the last 50 m. Otherwise retroreflective is fine. (Schedule 17 is pretty difficult to follow on this!)

DfT have clearly stated that in the new Regs electrical lighting on all signs within a 20 mph speed limits will be optional, including ones that are safety critical like 616 (no entry). So if their latest draft of the 2015 TSRGD says something different, that is clearly an error that will hopefully be picked up in the imminent "technical review and general sense check".

So I would only put forward for electrical lighting those 652s that are within 50 m on the start of a road (or a side turning at which you can join it in the relevant direction) and are unlikely to be within a 20 mph speed limit of either sort in the the near future. You might also wish to consider whether they are all actually needed or whether some can be removed completely.]]> Thu, 23 May 2019 09:24:01 GMT https://members.theihe.org/forums/posts.aspx?group=214541&topic=1489161 https://members.theihe.org/forums/posts.aspx?group=214541&topic=1489161 March 2015

Simon,

That's great advice, thank you.]]> Thu, 23 May 2019 09:24:14 GMT