Next A14 Upgrade

[roadtester]

I don't remember if it's been posted here before, but a few years ago there was a report with some initial concept of what a future upgrade of J33 might look like, which was published in the Milton village newsletter. I didn't think to keep an original copy but it was basically this (existing slips to be removed are shown in black):

milton.jpg

I'm not completely convinced that the existing bridges have enough span to allow for the extra offslip. But assuming this was actually checked when they came up with this, it doesn't seem like a bad idea. It would remove the set of lights at the top of the current EB offslip, which I would say is the main constraint on capacity in the evening peak.

It's certainly clever in its way, but I suspect it would just be buying a bit more time before a more comprehensive/expensive solution was needed.

[jackal]

The left turn is being provided as part of the current A14 upgrade.

The loop is interesting. A third lane over the bridge would be possible if they moved pedestrian access to an adjacent structure. Adding an additional ramp rarely seems to be considered in this country, despite the obvious advantages.

The other relatively easy upgrade would be a freeflow left turn for A14wb to the business park.

[sasas09]

The current scheme also involves widening the bridge to three lanes, as pedestrian access is already provided by the nearby cycle bridge.

[crb11]

The other relatively easy upgrade would be a freeflow left turn for A14wb to the business park.

Sorry, but no. (I work there.) There's no viable place to join a new road onto Cowley Road east of the cycle bridge, and if you go to the west side, you're digging into the embankment that the slip road is on, removing the trees which provide a visual and noise break from the roundabout, and joining into a narrow access road (15mph at best). The estate managers wouldn't approve of something which would effectively become a cut-through to Milton Road further south. And in any case, access to the park from that direction isn't an issue anyway apart from queues on the slip road itself as the turning off Milton Road has its own lane which is always free-flowing even in the rush hour.

[jackal]

The other relatively easy upgrade would be a freeflow left turn for A14wb to the business park.

Sorry, but no. (I work there.) There's no viable place to join a new road onto Cowley Road east of the cycle bridge, and if you go to the west side, you're digging into the embankment that the slip road is on, removing the trees which provide a visual and noise break from the roundabout, and joining into a narrow access road (15mph at best). The estate managers wouldn't approve of something which would effectively become a cut-through to Milton Road further south. And in any case, access to the park from that direction isn't an issue anyway apart from queues on the slip road itself as the turning off Milton Road has its own lane which is always free-flowing even in the rush hour.

I meant onto Milton Road, as a filter at the roundabout.

[crb11]

I meant onto Milton Road, as a filter at the roundabout.

In which case you're still going to have to get rid of the trees, and build up an embankment to put the new road on (the land slopes down quite steeply from the junction), for not a lot of benefit: if the area is clogged up anyway, the new filter will be blocked by the queues off the A14 and/or the queues down Milton Road. Compared to the other flows, A14w/b into the city is reasonably low in any case.

[camflyer]

I meant onto Milton Road, as a filter at the roundabout.

In which case you're still going to have to get rid of the trees, and build up an embankment to put the new road on (the land slopes down quite steeply from the junction), for not a lot of benefit: if the area is clogged up anyway, the new filter will be blocked by the queues off the A14 and/or the queues down Milton Road. Compared to the other flows, A14w/b into the city is reasonably low in any case.

I would agree with that. Even at peak time (9am on a weekday) the flow off the A14 w/b onto Milton Rd isn't that bad. It's very rare for traffic to backup onto the A14. The main problem with the sliproad is when it widens from 2 to 3 lanes so maybe better lane indicators would be welcome but I don't see the need for a freeflow lane onto Milton Rd or directly into St Johns.

The main problem at the moment is in the evenings when the westbound traffic backs up from the roadworks which means that sometimes it can take 20 minutes or more to get from the Science Park to the A14 eastbound.

[jackal]

Right turning westbound traffic is partly backed up the long red phase while eastbound traffic joining the roundabout has a green. Removing westbound traffic heading to Milton Rd from the roundabout entirely would allow the existing road space to be allocated entirely to right turn traffic (A10 and Milton), meaning it would need less green time and relieving eastbound queues. At present only half a lane out of three is allocated to A10 traffic.

In short, a signalized roundabout is a complex ecosystem, and making some parts of it work better (especially by removing traffic from it) will usually make all of it work better, sometimes in quite counterintuitive ways.

[crb11]

You seem quite determined to build this! It's been a while since I used that roundabout in the morning peak, but my memory is that the left lane was always emptier than the middle lane, and the latter was almost exclusively for A10 traffic (which makes sense - people wanting the City would generally take the emptier lane, and even if you wanted the righthand lanes on Milton Road, if you knew the junction you'd know you had plenty of time to get across). The limiting factor seemed to be either the amount of traffic you could get round the single lane onto the A10, or more frequently, a blockage from the queue waiting to get onto the A14W at the next lights round.

So I'm still unconvinced of the benefit of this. I'd change the signage to direct all the City traffic down the left lane, and I think something may be possible to prevent traffic going onto the A14W fouling traffic coming off the A14W (a yellow cross-hatched box, changing the signal timings perhaps).

[roadtester]

This will overload the roundabout even more - 6500 new homes on the site of Waterbeach barracks just to the north.

https://www.elystandard.co.uk/news/busi ... -1-6059943

[Berk]

Well... hmmm hmmmmm. We knew it was going to happen anyway. And I’m sure the developer is having to pay large amounts of 106 money as well.

We don’t really know what the road plans are going to be at this stage - or have I overlooked them?? I don’t think they’d be allowed to start construction until firm improvement plans and designs for the A10 have been submitted.

My biggest objection to that development is around the rail access. They want to open a new station for Waterbeach, close to the extended village centre (fine), but only as a replacement for the existing one (doesn’t meet modern standards).

What exactly is wrong with having two stations?? One for the centre, and another (the old one) for the southern suburbs?? It will still be a massive help to hundreds of other commuters and passengers every single day.

Yes, the old one will still not meet modern standards, but surely people with accessibility issues would prefer to use the new station anyway?? Perhaps to begin a journey, and they can always return to the old station if it’s nearer to where they live and the incoming platform is close to the exit??

[Phil]

Well... hmmm hmhttps://www.sabre-roads.org.uk/forum/posting.ph ... 053175mmmm. We knew it was going to happen anyway. And I’m sure the developer is having to pay large amounts of 106 money as well.


My biggest objection to that development is around the rail access. They want to open a new station for Waterbeach, close to the extended village centre (fine), but only as a replacement for the existing one (doesn’t meet modern standards).

What exactly is wrong with having two stations?? One for the centre, and another (the old one) for the southern suburbs??

Several things:-

It extends end to end journey times for current customers.
It reduces track capacity while trains slow down, carry out station duties, then accelerate - Twice.
It causes timetabling issues if train the extra time taken means do not hit junctions or single line sections at the right time.
It means there are two sets of station facilities to maintain - but you won't necessarily double the amount of customers to help pay for them both.
It could well mean extra drivers are required if layovers at each end slip below the minimums required.

All these factors mean it represents very poor value for money and you will not get a positive BCR for keeping both stations.

Down in Sussex near Crawley a new station has been proposed to serve a housing development but it can only go ahead if it replaces an existing one due to the adverse effects outlined above.

As ever people forget just how complicated and interwoven all aspects of the railway system are and the demands put upon it by current operations (passenger, freight and making time for engineering access) mean you cannot just plonk stations whenever you feel like it or add extra services at the drop of a hat.

Yes for historical reasons we do sometimes end up with stations close together in smallish towns - but this is NOT desirable setup for mainline rail systems (as opposed to dedicated metros / trams systems). Railways are not buses - their advantage is moving large numbers of people longish distances in a relatively short amount of time. Every station you add compromises this (unless said railway is set up as a metro operation like London's Overground)

[trickstat]

Well... hmmm hmhttps://www.sabre-roads.org.uk/forum/posting.ph ... 053175mmmm. We knew it was going to happen anyway. And I’m sure the developer is having to pay large amounts of 106 money as well.


My biggest objection to that development is around the rail access. They want to open a new station for Waterbeach, close to the extended village centre (fine), but only as a replacement for the existing one (doesn’t meet modern standards).

What exactly is wrong with having two stations?? One for the centre, and another (the old one) for the southern suburbs??

Several things:-

It extends end to end journey times for current customers.
It reduces track capacity while trains slow down, carry out station duties, then accelerate - Twice.
It causes timetabling issues if train the extra time taken means do not hit junctions or single line sections at the right time.
It means there are two sets of station facilities to maintain - but you won't necessarily double the amount of customers to help pay for them both.
It could well mean extra drivers are required if layovers at each end slip below the minimums required.

All these factors mean it represents very poor value for money and you will not get a positive BCR for keeping both stations.

Down in Sussex near Crawley a new station has been proposed to serve a housing development but it can only go ahead if it replaces an existing one due to the adverse effects outlined above.

As ever people forget just how complicated and interwoven all aspects of the railway system are and the demands put upon it by current operations (passenger, freight and making time for engineering access) mean you cannot just plonk stations whenever you feel like it or add extra services at the drop of a hat.

Yes for historical reasons we do sometimes end up with stations close together in smallish towns - but this is NOT desirable setup for mainline rail systems (as opposed to dedicated metros / trams systems). Railways are not buses - their advantage is moving large numbers of people longish distances in a relatively short amount of time. Every station you add compromises this (unless said railway is set up as a metro operation like London's Overground)

That doesn't surprise me that another station would need to close because Crawley itself has 3 stations. Possibly the smallest town to have this many?

[Chris5156]

That doesn't surprise me that another station would need to close because Crawley itself has 3 stations. Possibly the smallest town to have this many?

I see your Crawley (population 111,700) and raise you Pontefract (population 30,881) which also has three stations - Pontefract Monkhill, Tanshelf and Baghill.

[Chris Bertram]

That doesn't surprise me that another station would need to close because Crawley itself has 3 stations. Possibly the smallest town to have this many?

I see your Crawley (population 111,700) and raise you Pontefract (population 30,881) which also has three stations - Pontefract Monkhill, Tanshelf and Baghill.

Though Baghill has a very poor service.

[trickstat]

That doesn't surprise me that another station would need to close because Crawley itself has 3 stations. Possibly the smallest town to have this many?

I see your Crawley (population 111,700) and raise you Pontefract (population 30,881) which also has three stations - Pontefract Monkhill, Tanshelf and Baghill.

I've just checked and Dorking (11,185 in the 2011 census) also has 3 (on 2 different lines). Apparently, Dorking West is served by far fewer services than the other 2.

[Berk]

You also have Foxton, Shepreth and Meldreth very close to each other south of Cambridge.

Again, it seems to be a story of gold-plating standards...

That doesn't surprise me that another station would need to close because Crawley itself has 3 stations. Possibly the smallest town to have this many?

I see your Crawley (population 111,700) and raise you Pontefract (population 30,881) which also has three stations - Pontefract Monkhill, Tanshelf and Baghill.

I've just checked and Dorking (11,185 in the 2011 census) also has 3 (on 2 different lines). Apparently, Dorking West is served by far fewer services than the other 2.

Probably due to being on the North Downs Line.

[trickstat]

You also have Foxton, Shepreth and Meldreth very close to each other south of Cambridge.

Again, it seems to be a story of gold-plating standards...

According to Wikipedia, Shepreth and Meldreth opened along with the Hitchin-Cambridge line itself in 1851. The entry for Foxton doesn't mention when it opened. So basically it seems to me to be a case of stations never having been closed that wouldn't all have been opened if you were building such a line now. On the other hand, the existence of each of these stations probably does takes a little traffic off the A10. Perhaps if you were opening a line now you would have one station at Shepreth as the one in the middle to reduce the load on Cambridge and Royston.

[Berk]

Or Meldreth?? Seeing as it’s between there and Melbourn, and they’re both much bigger villages.

[trickstat]

Or Meldreth?? Seeing as it’s between there and Melbourn, and they’re both much bigger villages.

You may be right there as it gets about 50% more passengers than the other 2 stations combined.