Visibility splays

[Bournbrook]

Hi there

 

we are looking to build a new house in our garden and use the current driveway as the access for both houses. The current driveway goes straight onto a 20mph C road. 
the current visibility is not great (we don’t quite get the the nearside kerb 25m when looking left). As far as I understand, highways are only consulted when there is a change to the current access when it is under 5 dwellings. I understand it will attract a little more traffic (current house is 4 bed and new one is 2 bed) but the access remains unchanged. 
 

does anyone have any experience with this sort of thing and how much scrutiny we are likely to face? Looking at applications in my area, some seem to fly through with awful visibility and some are required to show very detailed plans that already have fairly good splays. 

Any advice welcome. 

[nod]

I’m not sure where you are but highways where consulted on both our builds Existing access being used 

[Temp]

No point in trying to guess how it will go.

 

There are ways to present your application. Site plans should show where the entrance is positioned but you don't need to show every tree or fence on it. It can be quite a minimalistic site plan/line drawing. Nor do you need to include photos of the existing entrance. 

  

Highways are busy and might not think a site visit is worth it if it looks OK on paper.

 

[Conor]

Each LA varies, but generally if it's a new dwelling, the access needs to meet the highways requirements. Regardless if it's the modification of an existing, or a new one.

[ToughButterCup]

9 hours ago, Bournbrook said:

... and how much scrutiny we are likely to face? Looking at applications in my area, some seem to fly through with awful visibility and some are required to show very detailed plans that already have fairly good splays....

 

There, you've done your Due Diligence.  Excellent. 

Now summarise all the local evidence online, know each case in detail. Then wait for the feedback.  Know the authors of each report. They'll each have their own style. 

 

Your rebuttal (of negative feedback)  will then write itself.  Make a tight well-argued evidence based rebuttal and the Planning Officer sees you as a less easy target. And so thinks twice.

 

Exactly what you need Best of luck 

Ian 

[ProDave]

A quick google tells me the stopping distance of a car at 20mph is 14 metres.  So if you are able to see 25 metres I would argue you have plenty of visibility.  At last we have found a way where these new 20mph limits may actually help you.

[Kelvin]

29 minutes ago, ProDave said:

A quick google tells me the stopping distance of a car at 20mph is 14 metres.  So if you are able to see 25 metres I would argue you have plenty of visibility.  At last we have found a way where these new 20mph limits may actually help you.

 

That’s wrong for visibility splays. They use a specific formula for calculating the stopping sight distance. For 20mph it’s 25m. Here’s the  formula: 

 

 

Your local council planning will have a guidance document on this. They are all generally based on the same document though. Get a copy, read it and apply it to your situation. As above don’t second guess what might happen just follow the guidelines. Just because you don’t quite meet the 25m it won’t necessarily stop you as the planning guide may well allow you to mitigate around it. This varies from council to council and will be specific to your situation. 

Edited October 8, 2023 by Kelvin

[ProDave]

So the council planner for visibility splays used a different stopping distance to that in the Highway Code?

[Timedout]

Highways conditions on planning consent are often there for the purposes o deterring development. The highways officer can operate on whim and will insert a tricky condition at the behest (not documented) of a planing officer. We have had it several times on our self builds. 
Favourite stunt in North Yorkshire.

push them for genuine reasoned conclusions, not just a standard answer or a whim. Especially on an existing access. We’ve done it successfully.

 

[joe90]

My new access was a nightmare, planners just said no, made up things (like I didn’t own land the splay was in, but we did) it was me that got highways involved after much badgering, when they turned up they said “no problem” but would not tell the council this, they would only “not object”. Only after quoting chapter and verse of their procedures to the appeal officer (along with appealing up the actual build) did I win on everything,         L@@dy  planners 🤯

 

so do your homework .

[ProDave]

Mine tried to apply a 90 metre visibility splay which would be hard to meet, until I pointed out they had approved another build in the same road with only 60 metre visibility, so they agreed to that.

 

It does seem to be a random number generation scheme,

[Kelvin]

1 hour ago, ProDave said:

So the council planner for visibility splays used a different stopping distance to that in the Highway Code?

It always has. Here’s an explanation blog on it. It’s more complicated because there are two standards a council might use depending on the road type. 
 

https://www.local-transport-projects.co.uk/did-it-just-get-trickier-to-provide-highway-access/

[Kelvin]

54 minutes ago, joe90 said:

My new access was a nightmare, planners just said no, made up things (like I didn’t own land the splay was in, but we did) it was me that got highways involved after much badgering, when they turned up they said “no problem” but would not tell the council this, they would only “not object”. Only after quoting chapter and verse of their procedures to the appeal officer (along with appealing up the actual build) did I win on everything,         L@@dy  planners 🤯

 

so do your homework .

 

Yep do your homework. Use their own guidelines against them and what they already agreed to in other planning applications. 

[saveasteading]

It's safety. Yours and your children's and your visitors'.

If you turn right and an oncoming  car hits the side of your car then that could be serious.

OK so they are supposed to be driving at 20, and braking vigorously. But they might be doing 30 and not paying attention.

You will creep out of the drive then put your foot down to reduce the chance of an accident.

 

That is why the rules are there. Planners won't care and will depend on Highways. Highways just want a piece of paper in the file that excuses them in the case of a claim.

That's all I want to say: over to you.

 

BTW 20mph saves a lot of lives and distress, but the current government are threatening to abandon the principle in a lives for votes equation. I don't know if Highways will consider that.

[joe90]

13 minutes ago, saveasteading said:

BTW 20mph saves a lot of lives and distress, but the current government are threatening to abandon the principle in a lives for votes equation. I don't know if Highways will consider that.

When my late wife worked in America she said  they had a system where main roads were 30mph but housing estates were 20mph, far more sensible IMO.

[SteamyTea]

1 hour ago, joe90 said:

When my late wife worked in America she said  they had a system where main roads were 30mph but housing estates were 20mph, far more sensible IMO.

They have many rules.

One is that if you want to overtake the school bus, you must physically stop your vehicle before starting the manoeuvre.

They have 4 way junctions as well. You all have to physically stop, then whoever was first their has right of way.

There is a roundabout in Boston, MA, that cause loads of confusion, thankfully there are a lot of British and Irish there, so it kind of works.

I got let off speeding because there would have been extra paperwork because I was an alien.

Did pass my driving test in Pennsylvania first time though. Dead easy.

[ProDave]

I found the 4 way stop worked well, everyone seemed to know when it was their turn.  But I can't see the average British driver doing that,  some would just try and barge in.  And yes they don't understand "traffic circles"

 

I think the overtaking a school bus is different in different states, where I was you were not allowed to overtake if it had some flag to show it was carrying children, you just had to wait while they got on or off.

[Alan Ambrose]

>>> I was an alien.

 

Presumably here to see whether this place should be demolished to make way for an intergalactic motorway?

 

Our plot is on a single track 'quiet lane'. You'd be hard pushed to do over 20, but that doesn't stop the utilities arguing that they need to close the road because 'people could be doing 60'.

 

On the original question - I think tread warily and stress that the current access exists already and won't be changed, which means the precedent is already set.

Edited October 8, 2023 by Alan Ambrose

[Crofter]

3 hours ago, ProDave said:

Mine tried to apply a 90 metre visibility splay which would be hard to meet, until I pointed out they had approved another build in the same road with only 60 metre visibility, so they agreed to that.

 

It does seem to be a random number generation scheme,

This was my experience too) Highland Council thing, perhaps?)

I could just squeak in to the requirement, but it relied upon vegetation being cut back on the verges for 90m either side of my access. This wasn't my land so the need to 'demonstrate control' couldn't be met. But they accepted it. My backup plan would have been to point out that it was their responsibility to trim back the verges.

A couple of houses built after mine, on the same road, had nothing like as good visibility, and still got through.

 

One other thing that came up for me was that my LA have two different access standards- one is for a single house, the other for a mini estate of up to four houses.

The junior planning officer who first dealt with my application initially demanded that I use the larger access, which physically wouldn't fit on the plot, because it would be shared between the house and the field behind it. Despite the field having alternative access, and fields not needing the same standard of access as a house. Fortunately he was over ruled by his boss who saw sense.

[Bournbrook]

Thanks everyone for your input. I have a slightly odd situation in that even though technically the current splays cannot be achieved within my land (due to a hedge right on boundary of next door - it’s not encroaching highway, I’ve checked!) when looking left out of drive. However, there is a traffic calming ‘buildout’ right next to our driveway, which accompanied with another directly opposite makes it almost impossible for 2 cars to get through separately. I’m banking on the fact that the x distance (which I can hopefully blag to be 2m not the 2.4) can be measured further into the carriageway (the blue line on my picture) as the buildout sort of acts like a verge. The official edge of highway is the red line. Does anyone have any thoughts??

[Kelvin]

They use the 85th percentile to calculate road speed so the speed 85% of drivers will drive past your entrance. Given your situation it’s likely people are driving significantly slower than 20mph, is that your observation? If so, it might be worth getting a traffic survey done. 

[Bournbrook]

2 minutes ago, Kelvin said:

They use the 85th percentile to calculate road speed so the speed 85% of drivers will drive past your entrance. Given your situation it’s likely people are driving significantly slower than 20mph, is that your observation? If so, it might be worth getting a traffic survey done. 

It is. However, I was under the impression it was ‘free flowing traffic’ they had to measure. Given the fact most traffic is waiting to pass through in turn, it is not free flowing. Also,as it is already a 20mph road, they won’t lower the visibility any lower than 25m either direction (as is my understanding), so a speed survey can only go against us I think!

our main hope is that the context of the buildout being there and therefore the ability of cars joining the highway to nose out into the road further than normal and therefore improving visibility in both directions. It’s a fairly unprecedented situation (as far as one can google anyway!) so I just wondered if people felt this was a valid point. I imagine it will just come down to the highways officer on the day!

[Kelvin]

While they might not lower the splay below 25m what you’re trying to show is that there’s reduced risk as a consequence of your unusual situation. If a survey showed the 85th percentile was significantly lower than 20mph you could use this to show the reduced risk. There’s nothing you can do about the free flowing traffic requirement (if that really is a requirement) 
 

I’d call a traffic survey company and ask them their advice. 

Edited October 8, 2023 by Kelvin

[Bournbrook]

7 minutes ago, Kelvin said:

While they might not lower the splay below 25m what you’re trying to show is that there’s reduced risk as a consequence of your unusual situation. If a survey showed the 85th percentile was significantly lower than 20mph you could use this to show the reduced risk. There’s nothing you can do about the free flowing traffic requirement (if that really is a requirement) 
 

I’d call a traffic survey company and ask them their advice. 

Yes, it is ‘free flow’. It comes from the technical guidance from the Highways Agency. 
 

I see what you mean regarding providing context rather than reducing ‘y’ distance. 

 

if it is picked up at planning, we will engage a highways consultant, but I just wondered what people thought of my argument of the buildout as a mitigating condition. It also just feels so random that some existing accessing onto classified roads are consulted on and some are not. Really frustrating for someone like me who spends time researching all of this, but can’t get a definitive answer. 
 

 

[kandgmitchell]

Well I'd just prepare a simple layout drawing using the build out as my reference for the highway edge, use the 2.0m "X" distance ( Manual for the Streets para 7.7.7) then use the 25m "Y" distance and show that. Could you widen your drive so as to push the centre line away from the neighbour's hedge and thus improve the splay?

 

Good luck - I'm arguing one where planning was refused on the basis that the vision splay of 56m wasn't shown in both directions as per guidance etc etc. The access is onto a one way street so I'm not sure why that's needed? Upon pointing this out Highways " are considering the matter" but another application will be needed!