This is a guest post by Jack Thompson. Jack is an engineer who has worked on civil construction sites in Canterbury, Waikato and Auckland. He writes in a personal capacity.

Why are the roadworks taking so long?

A previous guest post on Greater Auckland did an excellent job of breaking down why Temporary Traffic Management (TTM) is the way it is and the effort that goes into planning it. I won’t rehash that here. Instead I want to provide an insight into what goes on within the cones and fences. Why are the roadworks taking so long?

We’re all familiar with this polite warning.

Operating Lean

A common critique of roadworks is something along the lines of “When I drove by they weren’t doing anything, just a bunch of guys leaning on shovels.” This is based on seeing a worksite for maybe ten seconds out of an eight to twelve hour work day, hardly a statistically relevant sample size. Everyone on site has a specific role to play but that doesn’t mean they’re all occupied all the time. For example complex urban sites often have dedicated staff just for getting trucks in and out of site safely but when a truck isn’t there they just have to wait around.

There are seldom more resources on site than there need to be to get the job done. This is by design. Roadworks are generally done by contractors that are businesses, i.e. they’re trying to make a profit. It doesn’t make sense for them to have more staff, equipment or materials on site than necessary (although with staff there isn’t any choice because the whole industry is short-staffed.)

This operating model does introduce more ways for the job to be slowed down by something going wrong: A workmate might not be able to come to work because they’re sick. The digger might break down so you have to wait for someone to come and fix it or drop off a rental one. The pipes that got delivered might be defective and you have to wait for them to be replaced.

Road workers and excavator, possibly waiting for a spare part.

Why don’t clients force contractors to keep more resources on site to prevent shortages holding up the program? Because that would cost more and those costs would have to be passed on. Clients are generally service providers such as Auckland Transport, Watercare, Vector, Chorus and so forth. So increased costs will eventually be passed on to the public as taxpayers, ratepayers or bill payers.

What about improving worker productivity by investing in more training and new technology? Contractors already do this but the benefits don’t necessarily result in faster roadworks. They are more likely to result in working at the same rate with fewer staff. This enables contractors to win tenders by offering lower prices, which effectively passes on the cost savings to the client.

A Space-Time Continuum

With fixed productivity there are two ways of getting more done in a day: Using more space to allow more work steps to take place in parallel. Or using more time (working longer hours) to allow more work steps to take place in series. Usually roadworks can’t do either because they’re already operating at the limit of their regulatory constraints.

Let’s consider the example of laying a 110mm PVC duct all the way across a road. This looks like a standard house drainpipe except it’s usually colour-coded to whichever service is intended to be threaded through it later (orange for electricity, yellow for gas etc.) Existing services will need to be located first to avoid conflict. The trenchline will need to be marked out then the road surface cut using a concrete saw. A small excavator will be needed to dig out the trench. The duct will need to be laid in bedding sand then the trench backfilled. Finally the road surface will need to be restored using asphalt.

The fastest way to do this job is to close the whole road and dig the trench across in one hit. That way excavation, duct laying and backfilling can happen in parallel along the length of the trench. There’s no way AT (or other road controlling authority) will allow a road closure for such a minor job though. Depending on road width the work will have to be done in two or three sections using a contra-flow, one way system or stop-go setup. The lack of space will make the job take longer.

Working on one corner at a time, so everyone else can keep moving.

If the work site is on or near an arterial road then there will likely be work time restrictions on the traffic management plan, particularly during peak traffic. Another time constraint is that much of the equipment is noisy so its use at night will bother the neighbours and could result in an abatement notice from council noise control officers. This isn’t unreasonable, no-one wants a concrete saw (noise level exceeding 110dB) being used outside their house at 2am.

On a greenfields site this relatively simple job could be done in a day. In a city it could take two days if the crew is restricted to working in half of the road at once and only between 9am and 4pm. This loss of productivity can’t be blamed on any one thing but rather is the result of an accumulation of different constraints.

The Taniwha Beneath

Most roadworks require some kind of excavation. This carries the risk of there being something underground that the contractor hasn’t planned for. These ‘known unknowns’ include archeological finds, contaminated soils, unexpected ground conditions and underground services. It can be anticipated that they might be there but it’s impossible to be certain until the digging is finished.

Archeological finds usually result in all work having to stop until an archeologist has come in, recorded what’s there and confirmed it’s fine to continue digging. Most urban roads have been dug up so many times that this is relatively rare in the road corridor itself. On greenfields sites it’s more likely that something will turn up. Even finding something you think is an archeological discovery can create a lot of work.

Contaminated soils require extra care in handling them so that workers and the public aren’t exposed to them, which slows things down. This includes additional dust controls, personal protective equipment and encapsulated transport to special landfills. Long ago roads used to be built with coal tar, which is carcinogenic, so it’s not unheard of to dig this up. Other forms of contamination include heavy metals and asbestos.

Unexpected ground conditions are generally bad because they may require a change in methodology or even a change to the design, which could take weeks. Geotechnical investigations are done ahead of construction but they’re limited by sampling frequency and depth. This is evidenced by the problems caused with several large motorway projects in recent years. Look at the Waikato Expressway, SH2 Bayfair to Baypark upgrade, and the Christchurch Northern Corridor. Small projects run into similar problems but they don’t make the news.

There’s a lot buried beneath a typical urban road.

The most troublesome things under urban roads are generally services (aka utilities). These include electricity cables, telecommunications cables, gas pipes, potable water pipes, stormwater pipes and wastewater pipes, plus all the abandoned services. There are enough challenges to working safely around services that it’s worth a whole blog post in itself. Suffice to say that it’s difficult, time consuming and getting it wrong can have serious consequences.

Murphy’s Law

The construction industry in general faces a lot of problems (chronic staff shortages, cost inflation that far outpaces CPI, a cut-throat tendering environment pushing contractors to take on too much risk etc.) These underlying issues compound with the challenges of working in the road corridor.

In this environment any small problem has the potential to become a cascading failure. Consider a hypothetical situation where you’re the foreperson on a one-day job to install a service lateral (doesn’t matter which service) to a brownfields site in Auckland. It’s an arterial road so AT will only let you have the TTM in place between 9am and 4pm, which should be enough time. By the time the TTM is set up and the service locator has done their job it’s 10am. But they find a lot of unknown services so excavation has to be done very carefully, which slows things down. With hindsight you realise you should’ve got in a hydrovac truck. Then the excavator operator hits a previously unidentified pipe that was hidden under the other unknown services. This is a service strike so you have to stop work, get someone from head office to do an incident investigation and everyone will have to do a post-incident drug test. Now there won’t be enough time to complete the work before 4pm. You’ll have to cover the trench with steel plates and come back tomorrow. What was meant to be a one day job has become a two day job. The next job gets pushed back a day and so on.

This isn’t some dystopian worst-case scenario. Stuff like this is a daily occurrence around NZ. Seemingly everything that can go wrong, does go wrong at some stage. This is despite the best efforts of everyone involved.

It’s All Trade-Offs

I’ve spent plenty of time on site over the years, thinking about how we can do things better. The business imperatives, regulations and what’s actually underneath our streets aren’t factors that are going to change anytime soon. I have come to the conclusion that perhaps it is the best that we can hope for in the short term.

There is an explicit trade-off to be made between work duration and impact resulting in a continuum from short duration, high impact jobs to long duration, low impact jobs. At the former extreme is the principle on which much of the work on our rail network is done using weekends and public holidays for blocks of line. Most roadworks operate at the latter end due to the limitations already outlined.

In the end what level of disruption is considered acceptable to get a project done is not a decision for contractors. If a higher impact is considered a worthwhile price to pay for a shorter duration of roadworks then that needs to be negotiated between the client and the council (as regulators) after consulting the community who will be subject to the effects.

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31 comments

  1. Jack this is such a breath of fresh air compared to the impatient idealists (who are necessary) driving opinion here. While most here advocate for whole network changes, I’d always recommend taking a few months off from writing submissions and have a go with a shovel and a perpetual 7am start and taking the abuse as they seek to build those networks.

    Thanks for putting the reality of construction work and in particular your emphasis on client lower cost drivers and on the complexities of utility work in confined corridors.

    1. I think you’ll find a understanding of this is exactly what informs many advocates urging ‘no dig’ road-reallocation for the missing bike and bus priority networks over expensive corridor rebuilds. At least first.

      Agree the post is a welcome and clear reminder of these very issues.

    2. No, what the advocates here usually say is that we should be dealing with these issues while building *busways and bikeways*. Instead of, you know, yet another car lane, yet a another bigger traffic signals without bike lanes, yet another project that ignores safety for a short term car-focussed fix, yet another road re-seal that ignores sunken catchpits in cycle lanes or missing pedestrian crossings.

      Because every advocate who has been active for a while knows that once something is built it is bloody hard to change, and likely never will be changed. So we want it done now, yes. Rather than be told “this will be done by [Project X which is not yet funded and has already slipped into the future several times].”

      So I totally disagree with your comment’s gist – the people who complain about “bloody roadworks” are very often also the same people who say “if they weren’t spending all that [fictional] money on cycleways…”.

  2. How does the payment work? Does a contractor say I will lay the pipiefor$50,000 then if you find an archeological site the contractor wears the cost or can they get an adjusted up payment?

    1. Depends on the contract model that they’re working under. A basic fixed price contract may have the contractor wearing the cost, yes. However it’s more likely that the contract has provisions for cost sharing in the event of unforeseen circumstances out of the contractors control.

  3. Great post.

    You said the other way to get things done was to work longer days. If regulation was changed so on certain high value sites could work 24hrs a day would the construction industry be interested?

    1. Council would need to have issued very flexible noise level controls over night – this isn’t common. Generally after 2 complaints on the same night you get shut down.

    2. Agree with this that on certain strategic sites and projects we would benefit from having regulations that allow for 24 hour work in shifts. I think this applies to both some critical infrastructure and potentially also certain intensive housing developments (given the current crisis). Particularly where intensive residential is being built into formerly industrial zones where there are few current residents.

  4. Great post, thanks for the insights.

    It would be more complicated, but it seems New Zealand’s construction costs for these public infrastructure works are incredibly high. Especially the crl and pretty much any other rail project. And I’m sure road projects. It would be a much more complex thing to break down I’m sure. But a post on this subject would be helpful. People seem to think that contractors are milking it, but I doubt that’s the case.

  5. Really great post. Thanks.

    “the whole industry is short-staffed”

    I’m sure this is complex, but what do you see as the reasons, Jack?

    1. You’re right, it’s complex. Here are some quick things that I think are contributing reasons:
      – Not enough training up of new people between 1990-2010
      – No clear pipeline of work in NZ (hopefully being fixed by the Infrastructure Commission)
      – Competition for staff from Australia (better pay, bigger projects etc.)

      But this really deserves more research and its own post.

    2. There is one reason the industry is short staffed. The pay isn’t high enough. Remember that thing about supply and demand that David Ricardo came up with in about 1817?
      We live is a country where the main focus of Government microeconomic policy for 30 years has been to hold wages down. Whether it was employment relations, reform of funding models, government purchasing processes or immigration policy, the overarching goal has been to keep wages below inflation so the real wage has declined.

      1. Yes. Raised wages and training offered in-house should secure staff. Road maintenance has provided a steady pipeline of work, and will be into the future. The market has clearly been interrupted. Or could never deliver.

  6. Are there rules around the teams that rip up roads and footpaths putting it back as it was or better. Too often I see pavers ripped up and shoddy hotmix put back creating trip hazards.

    1. Yeah, that’s a weird one, isn’t it. It is up to the contractor to replace the asphalt, but as you’ve noticed, there is seldom any quality control involved. The onus is then on the Council to come back later, tear the whole thing up (both new and old), and do it again. Seems incredibly inefficient to me, and costly to the Council – ie to you and me, the ratepayers. But that just seems to be the way it is.

  7. If you want to run a 110mm duct across a road, the easiest way is by thrusting or directional-drilling from a hole dug on one side of the road to a hole dug on the other side of the road. All being well, the carriageway does not have to be disturbed at all.

    And by the way, I do wish the less-professional TTM installers would desist from obstructing road-shoulders (where cyclists ride) and footpaths (where pedestrians walk) with their signs and cones. It’s all too expedient to push the problem onto others, increasing the hazard for cyclists and pedestrians in order to mindlessly fulfill the TTM requirements for motor traffic. However, TTM done-properly works well and includes the needs of cyclists and pedestrians in the layout.

    1. Yes it is cost effective for the duct owner as the drilling can cut watermains, sewers and stormwater lines and nobody will notice until later, at which point the contractor is long gone and the owner of the duct can deny all knowledge.

  8. Thanks Jack. Excellent. Real.
    we’ve all witnessed roads being dug up, cables laid – followed by same road dug up, different cables/pipes laid and gone – who’s planning this…. if only…. – a couple of Questions ;-

    Magic thinking on my part :- but, are we missing the (expensive) step of building underground service shafts/corridors where we could manage those underground assets ? at least for green-fields developments.

    I’m guessing NZ’d experienced at dig/fix/patch (with all the issues you outlined) – do we future-proof service provision and maintenance ?

  9. Such an interesting post, thanks Jack! A great insight into the nitty gritty.

    I remember being amazed at seeing road crews working late at night on my first trips overseas – right in the middle of big cities. I guess the streets were so busy by day that night works made the most sense. Obviously no fun for residents nearby, but perhaps an inevitable trade-off given you get to “wake up in [a] city that never sleeps”…

    1. Trouble is in this Country all the Hotels within hearing distance of the works seem to have more power than they should have and some how can have those night works closed over a little noise .

  10. Interesting thanks. Yes after been kept awake the other night with nearly all night with nearby road works & heavy arterial road diversion past us I see why they don’t want to totally block roads & work 24hrs generally….though if I could afford double glazing…

  11. The past months we had a roundabout built on the intersection between Archers Road and Coronation Road in Glenfield. That looked, well, interesting, for similar reasons as in this post. Partial closures, stop-go with signals, building one side at a time. Maybe we’re too timid when it comes to closing roads for works. I feel overseas they would have closed that intersection and people would just have to live with the inconvenience for a few weeks.

    Although in this case it would be hard to get around this closure.

    An annoying thing is not signposting diversions further in advance. The Archers Road leg of that intersection was closed for a while. For many people the logical thing to do in that case is going via Sunnybrae Road and Coronation Road. However nothing was signposted at Sunnybrae Road so everyone was diverted through some small winding residential street. (this would be much easier if that intersection would be just closed for the duration of this job)

    An unfortunate detail was the design of the speed tables. To a layman it looks like they were drunk while building these things, but it was pointed out over here they are called Swedish tables and they’re supposed to be like that.

  12. Thanks Jack, i wonder if thrusting could be used more especially in peat country such as the Papakura Takanini area. Many of the cut streets and roads seem to have very poorly backfilling systems leading to successive failures over many years for the one cut.

  13. People have no idea what life is like working on the side of the road .I a contractor encounters lots of issues on a daily bases .E.G abuse for Joe public which is never a nice thing .This takes time in fact everything takes time .Some jobs take longer to complete due to changes In many cases when changes come along you have already programmed what your doing or have finished what your doing again this takes time and in most cases the contractor wont get paid as we have encountered . another issue Traffic management don’t even know we are coming onto site .in which ends up with contractors sitting on the side of the road for hours waiting to get on site again this is at the contractors expense.. Its a hard life been a road worker

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