Thoughts on UK Driving

[realjd]

So I just returned from a short trip to London. One of the days my wife and I rented a car and drove to Bath and Stonehenge. I figured I'd post a few thought on driving in the UK compared to the United States. Our route took us from the National Car/Europcar rental near the Marble Arch tube station, down the A4 to the M4 to Bath, along the A36 to the A303 to Stonehenge, then east along the A303 to the M3 to the M25 to the M4 to the A4 back to the car rental place.

• People seemed to drive better overall. Lane discipline was better and people seemed more courteous in general.
• Speed cameras everywhere, but extremely well marked.
• UK signage was excellent. Even in Central London, it wasn't hard to find your way around. I liked the signage on A road a bit better than the blue motorway signage. The motorway signs seemed overly wordy and cluttered in my opinion. I like American freeway signage better.
• I thoroughly enjoyed the national speed limit of 60 on 2-lane roads like the A36. Traffic was light and I was able to have fun with it.
• The Red+Amber phase on traffic lights wasn't particularly useful to me in an automatic car, but it was great as a pedestrian because it gave me an extra few seconds warning before cross traffic had a green.
• I like the roundabouts (although they seemed overused on rural roads). I don't like the big traffic circles in London. The fact that there can be 4 or 5 lanes of traffic in one of those big circles yet no lane lines leads to chaotic free-for-alls. In fact there were a couple of spots on the A4 in London that didn't have lane lines that were equally confusing.
• I noticed that parallel parking would sometimes block part or all of a traffic lane, and it was actually striped this way. You don't see that much in the US. People seemed to negotiate lane-use just fine around parked cars though.
• White-only lane striping wasn't too bad. Although my wife did yell at me once when she woke up from a nap and I was in the passing (right) lane on a dual carriageway where you couldn't see the other carriageway. She thought I was on the wrong side of the road!
• We saw numerous steep grades, the highest being 16%. In the US, we (usually) build switchbacks for roads like that. In typical British fashion, they just build straight up the steepest part of the hill. And then plant hedges overgrowing the sides of the road. And leave the speed limit at 60.

We had a great time in London and I thoroughly enjoyed our short road trip. We're already making plans to go back. And while not directly road related, I would also like to say that the London Underground is one of the best subway systems I've ever used. Trains were frequent and clean, stations were extremely well marked, and it's the only subway I've ever been on where the announcements are understandable.

[agentsteel53]

speed limits are in mph in the UK still?

[realjd]

Yep. The national speed limit (white circle with black slash) is:
70 mph - dual carriageway
60 mph - single carriageway
30 mph - built up area

A red circle speed limit sign overrules the national limit. There were a lot of 40 mph zones in towns and on bigger roads in London, and a few 20 mph zones in residential areas.

[agentsteel53]

is that the only context in which non-metric units are still used?

[Dr Frankenstein]

I noticed that parallel parking would sometimes block part or all of a traffic lane, and it was actually striped this way. You don't see that much in the US. People seemed to negotiate lane-use just fine around parked cars though.

Common in Montreal as well; and annoying, especially when there is only a small amount of cars parked.

[realjd]

is that the only context in which non-metric units are still used?

Not quite the only context, but close. The other big one is beer. It's sold in pints still (although British gallon/quart/pint is different from American gallon/quart/pint; 1 imperial pint = about 20 American fluid ounces). Temperature is in degrees C, most products at the store were in metric amounts (500mL soda bottles for instance), and gas is sold in pence/liter.

When we asked directions from a police officer to an open tube station during the mass demonstration last weekend, he told us the nearest open one was 500 meters down the road.

Confusingly, British road signs use "m" as the abbreviation for miles.

[6a]

Something I've always been curious about, but never bothered to look into.  What purpose do pavement markings looking like \/\/\/\/\/ serve?  From what I can tell, they appear to be near intersections, is it to warn that one is upcoming?

[realjd]

Something I've always been curious about, but never bothered to look into.  What purpose do pavement markings looking like \/\/\/\/\/ serve?  From what I can tell, they appear to be near intersections, is it to warn that one is upcoming?

Not intersections, they're near mid-block crosswalks. I'm not 100% on what the significance is other than to emphasize the pedestrian crossing.

[BrynM65]

Something I've always been curious about, but never bothered to look into.  What purpose do pavement markings looking like \/\/\/\/\/ serve?  From what I can tell, they appear to be near intersections, is it to warn that one is upcoming?

Not intersections, they're near mid-block crosswalks. I'm not 100% on what the significance is other than to emphasize the pedestrian crossing.

Zig-Zag markings are to denote where a 'controlled crossing area' exists - essentially, you are prohibited from parking and passing on the controlled area. The aim is to give pedestrians visibility.

As an aside, on older crossings you will still see a row of metal studs across the lane - these were the original method of marking the start of controlled areas but aren't easy to spot.

[Alps]

Metric/English unit discussion has been moved to Off-Topic.

https://www.aaroads.com/forum/index.php?topic=4366.0

[J N Winkler]

Confusingly, British road signs use "m" as the abbreviation for miles.

Motorway signs originally used to say "mile" or "miles" instead of using the "m" abbreviation, and also had fractions with bars.  However, ever since the Worboys signs were introduced in 1965, direction signs of all kinds have used the "m" abbreviation and fraction ligatures (i.e., fractions written with numerator in superscript and denominator in subscript with no bar, tiled as a single character per fraction in the Transport alphabets).  Design rules also call for a half space (not full space) to be used between the alphabetical and numerical parts of road designations, "m" and the mileage value, etc.

[agentsteel53]

fraction ligatures (i.e., fractions written with numerator in superscript and denominator in subscript with no bar, tiled as a single character per fraction in the Transport alphabets)

as in, the glyphs actually touch each other?

I would imagine that harms visibility but I suppose people can learn to recognize "1/2", "3/4", etc.

[realjd]

To be honest, I didn't even notice that there wasn't a slash mark in the fractions. They were perfectly readable as fractions without. But most of my focus on the motorway was on keeping the car centered in the lane; my mental autopilot is calibrated for sitting on the left side of the car.

A good example of unnecessarily complex British signage is when there is an exit only lane. Rather than include a note or simple indication that it's a lane drop like we have here, they have large signs with a diagram of the motorway showing explicitly that the lane is exit only.

Speaking of which, when there's an exit only lane and an option lane, they separate the two exits (exit only and option exit) by a buffer with crosshatching. I tried to find a picture but my Google skills fail me tonight. Does anyone know why they would do that, or have a good picture/example?

I will say that I'm a big fan of the way they do the stacked destinations on lane use signs. It's a much more elegant solution than California-esque multiple-arrow-per-lane type signage.

[J N Winkler]

To be honest, I didn't even notice that there wasn't a slash mark in the fractions. They were perfectly readable as fractions without. But most of my focus on the motorway was on keeping the car centered in the lane; my mental autopilot is calibrated for sitting on the left side of the car.

The adjustment does take some time.  What I have noticed is that the inside rearview mirror always seems to be more sharply tilted when I am driving on the left than when I am driving on the right.

A good example of unnecessarily complex British signage is when there is an exit only lane. Rather than include a note or simple indication that it's a lane drop like we have here, they have large signs with a diagram of the motorway showing explicitly that the lane is exit only.

If you are talking about the large ground-mounted lane diagrams, then these signs are nonprescribed (i.e., not shown in TSRGD or a "permitted variant" of a sign shown in TSRGD) and are not intended for general use at all lane drops.  They tend to be used at major system interchanges (e.g. M23/M25).  The vanilla approach for signing a motorway lane drop is to use a full-width gantry and put the exit legend on its own panel with its own downward-pointing arrow, ranged to the left of the sign containing the forward destinations (the local equivalent of the pull-through sign).

Speaking of which, when there's an exit only lane and an option lane, they separate the two exits (exit only and option exit) by a buffer with crosshatching. I tried to find a picture but my Google skills fail me tonight. Does anyone know why they would do that, or have a good picture/example?

The official term for this striping scheme is "anti-swoop markings."  They are so called because their intent is to discourage drivers from moving across multiple lanes ("swooping") to get into the exit ramp ("slip road") at the last minute.  The unofficial term, which has started to bleed back into official documentation, is "tiger tail markings" (so called because the hatching between the dropped lane and the exit lane that opens further downstream resembles a tiger's tail).

Another justification for the anti-swoop markings, and part of the reason they were developed in the first place, is that the traditional marking scheme for service interchanges on British motorways (which goes back all the way to the Motorway Design Memorandum circulated in typescript in the 1950's) called for exits to taper smoothly off the mainline into two lanes on the exit slip road.  This means that vehicles have to exit single file before they can access the two lanes, which has caused bottlenecking at busy interchanges as traffic volumes have increased at exits and on the motorways generally.  The anti-swoop markings now allow traffic to exit double file directly from the motorway mainline.

I will say that I'm a big fan of the way they do the stacked destinations on lane use signs. It's a much more elegant solution than California-esque multiple-arrow-per-lane type signage.

This is a relatively new approach, nonprescribed, and has come under heavy criticism since it deprives overhead signs of a consistent height profile.  Personally I think the German approach (now copied in the US to an extent with the new arrow-per-lane diagrammatics) is more efficient since it removes the need to stack signs vertically.

[J N Winkler]

A few additional thoughts about the differences between the UK and the US in lane drop signing:

*  In the UK designers still have the option of using ground-mounted signs for lane drops on motorways.  In the US there is no longer a comparable option for freeways.  (You can spot occasional examples of signs with bottom yellow panels reading "RIGHT LANE EXIT ONLY" or similar, but these are not MUTCD-kosher.)  TSRGD Diagrams 2904 and 2904.1 are the basic building blocks of ground-mounted lane drop signing.  Whether this option can be exercised responsibly on motorways with large truck volumes is a different question.

*  In the UK designers opting for overhead signing at motorway lane drops have to use pull-through signs; there is no option to omit pull-throughs at service interchanges with uncomplicated geometry, as is often done in the US.  (Cantilever mounting is basically not used on motorways except for VMS-type signing.)

Link:  Motorway signs as diagrammed in TSRGD

[realjd]

Searching for "tiger-tail markings" did lead to more information. That's exactly what I was looking for. It appears that "ghost island" is another term for the striped area between lanes. I still can't come up with a good example on Google Streetview though.

I was referring to the large lane use signs mounted on the side of the road, as well as the huge merge diagrams as seen in this flickr photo: http://www.flickr.com/photos/benagain_photo/2418418364/. It got the job done, but seemed unnecessarily large.

So the UK likes consistent sign height on overhead gantries? The stacked signs definitely don't follow that. I am also a fan of the Euro-style lane use arrows. I think they're much clearer than using multiple down arrows per lane and much clearer than some of the horrendous diagrammatic signs here in the US.

I also noticed that the UK likes to put the down arrows on lane-use signs in outside of the blue destination sign. I don't know if that's better or worse than the US way of putting them inside the destination sign (it probably doesn't matter either way), but it's an interesting difference.

[english si]

So I just returned from a short trip to London. One of the days my wife and I rented a car and drove to Bath and Stonehenge. I figured I'd post a few thought on driving in the UK compared to the United States. Our route took us from the National Car/Europcar rental near the Marble Arch tube station, down the A4 to the M4 to Bath, along the A36 to the A303 to Stonehenge, then east along the A303 to the M3 to the M25 to the M4 to the A4 back to the car rental place.

The A316 is rather good from the M3 to the M4, but the widenend M25 is fun. Also, from Marble Arch, I'd have taken the A40 out of London (though it's annoying to get onto from there). Perhaps better in-bound, as you can get off at Edgware Road.

I like the roundabouts (although they seemed overused on rural roads). I don't like the big traffic circles in London. The fact that there can be 4 or 5 lanes of traffic in one of those big circles yet no lane lines leads to chaotic free-for-alls. In fact there were a couple of spots on the A4 in London that didn't have lane lines that were equally confusing.

London is awful for lane markings. You found them overused on rural roads, because you spend a lot of time, on the A36, going on bypasses built in the late 80s, which were built on the cheap, and have roundabouts at every major-ish junction.

We saw numerous steep grades, the highest being 16%. In the US, we (usually) build switchbacks for roads like that. In typical British fashion, they just build straight up the steepest part of the hill. And then plant hedges overgrowing the sides of the road. And leave the speed limit at 60.

We have little space for switchbacks. There also aren't many 1 in 6 (16%) hills on major roads, though there are a few. And the speed limit is a limit, not a target. NSL is not a statement about the road being good for 60, but simply that they haven't bothered to change the limit.

Here's a Tiger Tail sign and here is the actual thing.

We had a great time in London and I thoroughly enjoyed our short road trip. We're already making plans to go back.

I never get tired of London and there's tons I haven't done, despite living close by and visiting quite a bit. Plus there's the bonus of there being places such as Bath and Stonehenge (to name just the two you visited) within easy reach for a day trip.

[J N Winkler]

Searching for "tiger-tail markings" did lead to more information. That's exactly what I was looking for. It appears that "ghost island" is another term for the striped area between lanes. I still can't come up with a good example on Google Streetview though.

To add to the example Si supplied, here is an aerial view of tiger-tail markings at the merge where the M40 Oxford spur joins the M40 mainline going eastbound:

http://maps.google.com/maps?q=High+Wycombe&ie=UTF8&hq=&hnear=High+Wycombe,+Buckinghamshire,+United+Kingdom&ll=51.731092,-1.072267&spn=0.001691,0.004823&t=h&z=18

I was referring to the large lane use signs mounted on the side of the road, as well as the huge merge diagrams as seen in this flickr photo: http://www.flickr.com/photos/benagain_photo/2418418364/. It got the job done, but seemed unnecessarily large.

Those signs, which are in fact prescribed, are typically used for merges with unusual lane configurations.  There is actually a document (part of the Design Manual for Roads and Bridges, a large compilation of advisories which used to be available as a set of looseleaf binders but which is now on the Web in its entirety) which sets forth the conditions under which these signs are to be used in lieu of the triangular warning signs (similar to the W-series merge warning signs used in the US) which are meant for use at simple merges.

Initially I thought you were talking about these signs:

http://maps.google.com/maps?q=Merstham&ie=UTF8&hq=&hnear=Merstham,+Redhill,+United+Kingdom&ll=51.256997,-0.125177&spn=0.003444,0.009645&t=k&z=17&layer=c&cbll=51.256997,-0.125177&panoid=Mgjk7uhOCNewZCdiiQFuwQ&cbp=12,327.42,,0,-5.11

These are definitely nonprescribed, although there are ongoing efforts to systematize their use on the trunk road network.  Note the diagrammatic representation of the ghost island, and also the design differences compared to the M20 sign Si linked to.

BTW, here is an in-field example of a sign to Diagram 2904:

http://maps.google.com/maps?q=Merstham&ie=UTF8&hq=&hnear=Merstham,+Redhill,+United+Kingdom&ll=51.235416,-0.117706&spn=0.003446,0.009645&t=k&z=17&layer=c&cbll=51.235416,-0.117706&panoid=-SgRxNsgD6P9LfxIo59Khw&cbp=12,342.98,,0,2.4

This is an advance direction sign (the first, I think) for the M23/M25 stack on the M23 northbound.  Note that it shows only a simple lane drop, unlike the tiger-tail sign further downstream which shows an option lane separated from the dropped lane by a ghost island.  What this means is that the signing at this interchange "hides" the option lane until traffic is about to exit, much like MUTCD 2009 now requires.  (BTW, Merstham is the British answer to stacks like I-5/SR 4 in Stockton and I-695/I-70 in Baltimore.  The M23 was meant to be extended northward into central London but this attracted such heavy opposition the scheme was cancelled in the early 1980's.)

So the UK likes consistent sign height on overhead gantries? The stacked signs definitely don't follow that. I am also a fan of the Euro-style lane use arrows. I think they're much clearer than using multiple down arrows per lane and much clearer than some of the horrendous diagrammatic signs here in the US.

I think this just goes to show that option lanes cause signing problems everywhere--not just in the US.  I think the British just don't like the idea of using upward-pointing arrows on overhead signs for lane assignment ("not invented here" syndrome in operation?), and this holds them back from devising variants of the German and American approaches for their own network.

I also noticed that the UK likes to put the down arrows on lane-use signs in outside of the blue destination sign. I don't know if that's better or worse than the US way of putting them inside the destination sign (it probably doesn't matter either way), but it's an interesting difference.

The UK has gone back and forth on this in the past.  I can remember past editions of the TSRGD (1975, maybe 1964) which showed arrows on the sign panel as an option for motorways.  Somewhere along the way, maybe in TSRGD 1981, this option was dropped for motorways, though it is still available for all-purpose roads (whose direction signs have white background on non-primary routes and green background on primary routes).

[agentsteel53]

We have little space for switchbacks. There also aren't many 1 in 6 (16%) hills on major roads, though there are a few. And the speed limit is a limit, not a target. NSL is not a statement about the road being good for 60, but simply that they haven't bothered to change the limit.

this sounds similar to Quebec's principles for road design.  to the east of Montreal, where the last of the Appalachians come into Canada, quite a few roads are made to a grid and have 13-14-15% inclines.  

as for the limit staying 60 - good for them!  if I can take 15mph advisory curves at 52mph in my BMW Z3 or whatnot, I shouldn't be prevented from doing so.  Speed limits should only drop if there's lots of high traffic, pedestrians, and other risks to others besides yourself.  If I want to fall off the cliff and die, that should be my decision.

[J N Winkler]

as for the limit staying 60 - good for them!  if I can take 15mph advisory curves at 52mph in my BMW Z3 or whatnot, I shouldn't be prevented from doing so.  Speed limits should only drop if there's lots of high traffic, pedestrians, and other risks to others besides yourself.  If I want to fall off the cliff and die, that should be my decision.

Nope.  The limit stays 60 on these roads largely because of differences in engineering practice and driver licensing procedure, not because the decision-makers put serious stock in Fountainhead libertarianism.  Advisory speeds are generally not signed and you are expected to have the skills to choose an appropriate speed for these roads before you are licensed.  But because no individual has the right to run up NHS charges for everyone else, highway authorities can and will reduce the limit (often to arguably ridiculous levels with poor compliance unless speed cameras are provided) if a convincing case can be made for harm reduction.

[agentsteel53]

Nope.  The limit stays 60 on these roads largely because of differences in engineering practice and driver licensing procedure, not because the decision-makers put serious stock in Fountainhead libertarianism.  Advisory speeds are generally not signed and you are expected to have the skills to choose an appropriate speed for these roads before you are licensed.  But because no individual has the right to run up NHS charges for everyone else, highway authorities can and will reduce the limit (often to arguably ridiculous levels with poor compliance unless speed cameras are provided) if a convincing case can be made for harm reduction.

I presume, then, that for a lot of the more rural roads with hardly any traffic on them, the speed limit will not ever get lowered to some absurd number like 25mph, with a cop by the side of the road (or, in this case, a speed camera) for the purposes of generating a few extra quid for Ye Merrye Communitye of Shropshire-upon-Trout.

[J N Winkler]

I presume, then, that for a lot of the more rural roads with hardly any traffic on them, the speed limit will not ever get lowered to some absurd number like 25mph, with a cop by the side of the road (or, in this case, a speed camera) for the purposes of generating a few extra quid for Ye Merrye Communitye of Shropshire-upon-Trout.

Yes and no.  Low-volume rural roads tend to be ignored because the absolute traffic volumes are low.  However, roads with unusually high rates of fatal accidents tend to attract attention when they come to the top of spreadsheet sorts.  Police authorities in the UK are completely separate of local councils and, aside from a short-lived experiment with safety camera partnerships, there is no sharing of revenue from fines, so revenue-trapping in the American sense is almost nonexistent.  But if a local authority officer is persuaded that NSL on a given road should be cut to 40 for the good of the community, it will happen and the speed cameras will go up.

[agentsteel53]

that still sounds to be several orders of magnitude less corrupt than the US way of doing things.  

dunno how the US, with its much greater belief in federalism, could adopt such a thing, though ... here, by definition, the police authorities and the equivalent of the local councils are very much tied together.  

I'm quite certain most folks would rather have a speed trap, than the federal government coming in and telling them what the speed limit should, or should not be.  Maybe the state government can get away with it... at least, on the sly, like the rumor of Tallahassee tearing up any speeding ticket out of Waldo for less than 5mph over the limit.

[realjd]

J N Winkler,
I was talking about both of the signs pictured. I lumped them together under the heading "big blue signs with arrows". Thank you for the examples.

english si,
I chose the A4 for a few reasons. Primarily, I was too cheap to rent a sat-nav with the car and it looked like taking the A4 to the M4 resulted in the least number of ways to get lost. Also though, it got me onto a motorway more quickly (or at least in a shorter distance). On the map at least, the A40 looks like a green road almost all the way to the M25. Would it really be quicker? I had visions of a slow suburban road with constant stoplights, traffic, and driveways.

The reason coming back that we took the M25 and not the A316 was that I didn't remember where the M3 went past the M25 and my wife with the atlas was asleep. The M25 was impressive, speed camera density aside.

Being in London during the big protest and the riots was definitely interesting. It sure made for a memorable Saturday afternoon.

[english si]

The A40 is the best route between the Inner Ring Road and M25 - there's an iffy bit between the A219 and A406 junctions, with a couple sets of signals (two or three ped xings, one or two road junctions), but the rest is effectively freeway. The bit between the A501 and A219 was motorway, but downgraded when TfL took over it from the HA. Even the bad bit is better than the A4 through Kensington. There's a bit of difficulty getting onto it from the A5 (ask the rental place), but other than that it's a better option to remember for next time.

Then again if you want the M4 or M3, the A4 is far from a bad idea, and perhaps better. I forgot how easy it is to get to the A4 from Marble Arch.