General

Proposed Cobham Drive traffic lights a cheap, nasty, and potentially unsafe option – why can’t we have nice things?

Let’s Get Wellington (not) Moving has mooted a pedestrian traffic light system being placed right over one of the busiest arteries in the City, Cobham Drive, an increasingly congested road that is critical because it allows access to and from the airport.

Reading between the lines this is an effort to increase safety for pedestrians trying to cross the busy roadway and its a cheap option, because over-bridges are more expensive.

One of the first steps to get Wellington moving could potentially slow it down.

A traffic light-controlled pedestrian crossing on busy Cobham Dr, on State Highway 1, is expected to be one of the first projects completed as part of the multibillion-dollar Let’s Get Wellington Moving (LGWM) programme.

Traffic lights preferred option for pedestrian crossing on busy route to Wellington airport

Despite the fact (of which there are almost none when it comes to LGWM) that this will go to public consultation, Chris Calvi-Freeman as already come out in favour, declaring his hand.

But Calvi-Freeman said the crossing would have a minimal effect on traffic. It would be split on either side of the median strip, with one set of lights for the two eastbound lanes and another for the two westbound lanes.

“In the off-peak it wouldn’t be triggered very often. And in the peak hours, when traffic is very heavy and slow-moving anyway, it wouldn’t make a jot of difference.”

I’m guessing that Chris doesn’t use Cobham Drive that often. It’s a diabolical road at the best of times and when you add in frequent sun-strike over winter in both directions, days of heavy weather, and the surges in traffic make it downright dangerous.

Even if traffic is backed up to the airport, which it frequently is, the areas where they are mooting a traffic light pedestrian crossing are often filled with fast moving blocs of cars as they negotiate the primary roundabout. It’s completely disingenuous to suggest that it won’t make a jot of difference.

It will absolutely increase congestion on that road. Similar installations around the city and countryside have proven that fact. The lights cause surges, the surges cause waves, and traffic congestion goes up.

The argument is that it’s safer. Well, the fact is that any traffic light pedestrian crossing will increase accidents, and most obviously, between cars and pedestrians or cyclists.

Hu’s model for predicting accidents revealed that traffic-light-controlled intersections are more than nine times as likely to have fatal crash incidents involving cars and bicycles or pedestrians than expected by chance in Houston. In comparison, intersections with stop signs were only 1.48 times as likely to have a fatal crash incident, and noncontrolled intersections were 0.5 times as likely to have a fatal incident.

Traffic-light-controlled intersections found to attract fatal accidents

Nine. Times. More. Likely.

Often we see projects either fail, or have unintended consequences, when the cheapest option is chosen. Couple that with the corporate phrase “low-hanging fruit”, and you have a recipe for disaster.

In fact, another fact, in nearly all services contracts where the lowest option is chosen, failure is assured. Take the recent bus contracts as an example that is close to home.

“Low-hanging fruit” is usually the fruit that wasps inhabit.

As I was perusing Twitter I came across a post from one of the local cyclists who suggested a “Hovenring” as opposed to pedestrian controlled traffic lights. As you can see from the image at the top of this post it is a thing of beauty, allowing pedestrians and cyclists completely safe access across the road.

But it’s too expensive is the cry.

Is it? The cost of accidents to pedestrians, cyclists, and drivers is gigantic in New Zealand. The emotional impact on families and the community is uncountable. The cost offset of putting in a safe access across Cobham Drive can be offset by this.

How much would a hovenring cost?

For a long time it was a bit mysterious what this bridge had cost because the amounts were mostly including the whole redesign of the carriage way. IPV Delft now mentions on its website that the “construction costs” of the Hovenring itself were 6.3 million Euros.

Spectacular New Floating Cycle Roundabout

Now, we could reduce the cost of a full hovenring (it may be that we can’t build one in that style given it’s proximity to the airport regardless), by simply making it a standard over-bridge of some description. It may still be some millions, however, the average cost of an accidental death in New Zealand is in the range of $4 million.

Given that LGWM is planning to spend billions it does not seem unreasonable to spend some millions on an over-bridge or hovenring-like construction.

But we can’t have nice things because we always want the cheapest option, based on 1950’s traffic planning it seems, as fast as we can because it is “low-hanging fruit”, with no thought for unintended consequences.

The best thing about a hovenring style construction would be that everyone remains happy. Pedestrians, cyclists, drivers, and transporters.

But we are not allowed nice things. And until we change the way we plan, we’ll continue to get congestion, accidents, and all the downsides of both.

Updated: Make yourself heard. If you think an over-bridge is a good idea, you’ll find a petition here. It’s already been signed by more than 6,000 people.

6 replies »

  1. Calvi-Freeman doesn’t live on the Peninsula so he doesn’t have to use Cobham Drive every day. On top of that he is a pompous ass. The hovenring looks beautiful.

    Like

  2. Oh dear, I’m very upset now. I realise the error of my ways and will immediately advocate for a hovenring at every available site. To whom should I send the invoice? Best wishes CCF

    Like

  3. I’ve been asking for some cost estimates for the various options for Cobham Drive, in light of LGWM’s recommendation for signalised crossings.

    It appears that signals here would cost about $200k or upwards. Seems like a lot of money but there are all sorts of supporting paraphernalia. An overbridge would be around the $2-3 million mark (subject to confirmation). Again, seems like a huge sum but any new structure has to (and should) comply with disabled access regulations, which means very very long rmaps with shallow gradients and level rest points at intervals up and down the ramps. There would also need to be a fence along the median strip to discourage people from crossing the road at that point. I will continue to seek confirmed figures and a full analysis of the options, including a traffic delay analysis.

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s