There seems to have been plenty of LED upgrades and new junctions going in recently and signal upgrades in general seem to be on the up again around here.

However it seems to me that in many cases there seems to be an over-installing of traffic signal heads and columns. For example, 4 signal heads may replace 2 old Mellor heads, and the junction layout may not have changed at all.

The main one for me is Puffin crossings, or Pelican to Puffin conversions. Simple 4-RAG head crossings (2 heads per approach) now having 8-RAG heads (four heads per approach) etc.

A recent installation that annoys me every time I travel around the junction is the new lights at the Preston end of the M65 where it meets the A6. There are as many as 7 or 8 signal heads facing one approach, including some columns with two RAGs facing the same approach, side by side (I've attached some pictures for those who haven't seen it). Meanwhile, the M65/M6 roundabout just a stones throw away has the traditional 2 primary and 1 secondary head for each approach, plus the additional high-level heads for the M65 off-slip, which in my opinion is much more suitable.

Is it just me that is noticing this, or is it happening elsewhere too?

I've noticed it too here in Birmingham, there does seem to be an "arms race" effect. Ped crossings can have three or four heads in each direction at normal level, plus the option of totem pole high-level heads or even a mast-arm two-header. Major junctions now routinely get totem poles on both sides plus multiple secondaries.

Is it now considered bad practice to go for the minimum requirement only?

Absolutely not!

If I can get away with two lanterns on an approach I will do. It costs a serious amount of moolah to run signals, and the less I have to pay, the better for my council tax.

At the end of the day, it's my own personal money that I am essentially spending, so the less I spend on equipment, maintenance and energy, the more I can do with what I do have.

Need you up in Dundee!
Someone's got shares in Siemens...

Old proverb.

Two heads are better than one.

Dundee does seem to like its signal heads although there's a lot worse elsewhere. There are now some junctions where, at night, you'd be forgiven for thinking that you were approaching a 70's disco.

As Chris Bertram has said, a common thing that I'm starting to notice is the replacement of bog standard old two headed pelican crossings with a puffin crossing such as this.

I remember seeing a picture of this crossing (IIRC it was this one anyway!) some years back.

Just down the road is this... Which probably just falls under bad signal design - looking at it from the other direction particularly.

Someone definitely had shares in Siemens on these ones!

So common. Indeed I look at some junctions and when you see all the guard railing, signage, signal poles and lighting it is so cluttered and unnecessary.

My favourite is this- http://goo.gl/maps/Pm3Ef

A lot of signals designers go by the "number of signal heads = number of lanes + 1" rule of thumb. It isn't written down anywhere, but generally ensures sufficient signal heads without overcluttering the junction.

That would leave most junctions with 3 heads per approach then, assuming there were right turn lanes. I'm still firmly of the belief that most approach (ahead/left and right or similar) can be catered for with only 2 signal heads.

Another one that really winds me up is the over-use of columns. I appreciate PBUs may have to be in a certain place, but when there is just a Puffin PBU and nothing else at all on a column, its a waste and looks incredibly untidy - what's wrong with a short column? Things like this too. There seemed to be a trend not too long ago whereby the secondary heads got a column all of there own...

In one of the first pictures from Simon I've never seen two signal heads on the bottom of a tall pole for the same phase before, totally over the top.

The only thing wrong with the Puffin Crossing linked in the quote above is the use of nearside signals on the wrong poles facing away from oncoming traffic. Aside from that I think that's a sufficient number of signals.

Simon, You'll generally see 'empty' standard poles used with Nearside units as you may need somewhere to place the on-crossings or kerbsides if you are using them. It does look a little silly to use lots of empty swan neck poles as the purpose of the swan neck is to get clearance to a signal head, if the designer never intends to install a head they should use a straight pole in my opinion.

Interesting how the US can do a complete 4-way intersection with ONE head, with four faces, suspended in the middle of a diagonal cable strung across the junction between two poles at opposite corners.

Once said to me by an old engineer that "there are salesmen from traffic signal manufacturers, but no salesmen for roundabouts", and this is true. The comments above about having shares in a signal manufacturer are not really accurate, more is having a zealous area salesman paid on commission.

Over-provision of any signage is often dependent on the accident record, maybe just one which becomes prominent to politicians. I recall back in the 1960s a multiple fatality collision at an uncontrolled cross roads in the back streets of Birkenhead. Subsequently there were erected a forest of Give Way and Advance Give Way signs, bollards, markings, etc, notwithstanding that the principal cause of the fatalities in what must have been a low speed collision was having excessive unsecured children in a Dormobile which was overturned. A generation on and the junction has gone back to standard signage.

As funny as that is I've not seen much truth to it as the overprovision of signals I think is more due to novice signal designers who lack the confidence, experience or guidance of more senior engineers to design at minimum and defend against the over use of signals that come from fear, safety audits and some 'bottom covering' practices.

Ah the old Crouse-Hinds 4-way signal. I don't think that's still allowable in current practice, though there may be some legacy instances around.

Anyone care to guess how many signal poles there are at this at-grade S4 x S4 junction? If you like, count them on Streetview, and see if you get the same answer as me. I think it might be a record for a crossroads!

This roundabout is quite close to my house, and I was going to post about it when the signals were installed a few months back as they had a few botches, but didn't as I couldn't get photos in time.

On the approach to the roundabout from the A582 the arrow aspects for the sliproad towards Preston didn' match up. The signals consisted of 5 separate heads, two on two totems either side of the slip then one set back on the splitter island. However the two lower signals on the totem showed green "straight on" arrows, the two upper signals on the totem showed 45 degree "left turn" arrows, and the one on the island showed a 90 degree "left turn" arrow. Worst bit was the "straight on" arrows conflicted with the mainline movement onto the roundabout. Thankfully its all fixed now but I wish I had got some pics beforehand!

Also you will find PBU on poles in the central roundabout island, when there isn't any footpaths crossing, and they were still there a couple of weeks ago...

EDIT: This is the location I am on about, before the signals were installed : https://www.google.co.uk/maps?q=lostock ... 68,,0,5.48

The preferred option is still for just one signal head on the farside of the intersection - this to me is unsatisfactory as there is no guard against failure; at least the French use the low level repeater for the first car (I love those as a design).

Not just the French, I'm sure I've seen them in Spain and Italy too.

Even if you're not using OCDs and KSDs, you'll need somewhere to terminate the cables which is why a full-height pole is often used. I agree that a 4m pole with only a detector, or nothing, on top does look silly though.

I may soon have something to do with Dundee if I'm lucky so hopefully I can sort them out

I was driving with these last week in France and find them counter-intuitive, as when you are at the stop line you need to look more about 60 degrees to your right to see it, whereas at a comparable UK installation (and indeed at US one-head-wonders over the middle of the junction) you are looking ahead. I am conscious in France that as you come to a stand at the line the main signals just disappear from your field of view.