Â鶹´«Ã½

How to spend wisely

Firstly, understand your network. Sometimes, it¡¯s the simple things that can be the most revealing. Analysis of crash data and history provides important information like:

• Where crashes regularly occur.
• The types of crashes that occur.
• Other contributing factors.

The NZ Transport Agency¡¯s Crash Analysis System (CAS) has some great data that can provide greater details to get the whole picture. For example, a previous initial network analysis revealed that a high percentage of crashes occurred in the dark. A more detailed analysis then revealed that many of those crashes occurred along three distinct routes. These three routes accounted for a high percentage of fatal and serious crashes.

Second, understand your future risks. What is the condition of the network, and can you quantify it? Identify the locations that could cause a problem in meeting the government¡¯s road safety objectives.

By utilising tools to evaluate and rank sites, we better understand where the real problems are. This approach also gives us a defendable position based upon clear engineering judgement. Using a multi-criteria analysis (MCA) process also allows us to evaluate both tangible and intangible elements in a structured and repeatable way.?

Third, it¡¯s important to prioritise. A good starting point is to have a system that ranks sites, areas, or routes on a risk basis. This also helps you explain why you completed the work in a certain way. It¡¯s been my experience when called to the stand in the Coroners Court that demonstrating a robust prioritisation process is critical in gaining greater acceptance of the outcomes.

Finally, it¡¯s critical to review your outcomes. Make sure any key-performance indicators align with your road-safety goals and ask yourself if they measure the right elements. Following is an example for unprotected embankments.

• Unsafe embankments that require protection = 600 (identified through a robust assessment process)
• Available funds = $200,000
• Top 10 sites (covers 35% of fatal and serious injury crashes) = $250,000 (construction cost)
• An analysis of the network indicates that 52% of crashes occur in the dark. This suggests that there are nighttime delineation and advisory sign issues. As a result, you need to check if your maintenance intervention systems allow you to understand the condition of your delineation and signs at night. Do you truly understand the nature of the problem on your network?

The challenge of nighttime signs

My recent experience over several networks has shown that many signs are ineffective at night, yet they remain a key channel to communicate a message to a driver. What can appear yellow and effective during daylight may be ineffective at night. The performance of retro-reflective material degrades with time and its condition is not always apparent in daylight.

Replacing ineffective signs may also prove cheaper than rehabilitating a site. An out-of-character curve on a section of road could be gated with signs and improved delineation for a more reasonable cost than capital or minor safety works.

Be sure to determine if the site/route/location can be made safer with additional signs and treatments.

Consider holding patterns

Are you able to defer pavement rehabilitations or reconstructions using waterproofing seals and improved guidance? Setting speed environments to isolated sections of our network may be more effective than undertaking costly road realignments. The Setting of Speed Limit Rule will assist with this when released. By applying a speed environment, you can install gated advance warning and legal speed limit signs to signify the change, with an appropriate treatment on the successive curves throughout the length affected.

Avoid confusion

Sites often have a multitude of signs, markings, and roadside elements that confuse the driver.

The brain needs three reference points on a curve to understand the degree of curvature, so guides should be located where they benefit the driver. Further, all chevrons and curve warnings should be equidistant from the road edge and mounted at the same height relative to the edge line. This helps to define the ¡°shape¡± of the curve.

This simple method may also remove the need for expensive rehabilitation works or hold the site until such works can be undertaken later.

Conduct safety-focus inspections

We often drive over our network thinking about multiple tasks. Ensure you take the time to drive over the problem areas of the network while thinking specifically about safety.

Look at the road from the general public¡¯s point of view. Ask yourself: Is the driver getting the right message at the right time? It¡¯s often the things we can¡¯t see, rather than those we can, that cause the largest problems. It¡¯s easy to identify a damaged sign but not a missing one. Think about whether there should be a sign on that approach to a curve or intersection.?

Consider sight lines

When you receive complaints about near-hit events along a road section, view a video of the road¡ªGoogle Maps is a good default tool¡ªto determine if it is an open section of road with some vegetation. Remember that a site can appear OK in a video, but a visit may uncover that the vegetation has grown and now blocks the inter-visibility sight line between two vehicles. In this instance, a simple trimming of vegetation on the shoulder of the road may be all that it takes to eliminate a problem.

Consider the design from start to end

New designs, especially in an urban area, are often fraught with problems. Beautification would have us install planting and objects at an intersection to create a more attractive environment due to the unsightly look of concrete and asphalt. We soften the ¡°hard¡± edges with vegetation.

Our landscapers or urban designers assess whether a certain type of plant or tree would be best for the given location and environment. The landscape plans look appealing and feature full-grown trees that meet the desired outcome. However, during development we usually plant young trees with a low height that often places the canopy at the driver¡¯s eye height. A simple solution is to plant larger trees, something that might take years of forward planning to ensure they are available at the time of construction.

Ensure you consider these aspects early in the design. Ask the questions from a road-safety perspective and then develop a strategy.

Look at the network-wide approach

One study of a rural network indicated that many vehicles crashed into utility poles along a specific route. When viewed separately, each crash did not justify installing a safety barrier, but when viewed collectively, along with the associated crash social costs, it justified a fundable treatment to move the utility poles underground. Until such a move happens, you should also consider temporary solutions to keep the area safe.?

I¡¯ve previously investigated two fatal crashes in a short timeframe that were around 500 metres of each other on a length of road in an open road environment. Both crashes may have had better outcomes had there been no utility poles roadside.??

In such circumstances, you should discuss with the utility provider whether they can relocate or remove the utility poles. Explain the situation and work with them to formulate a solution, both temporary and more permanent. In this case, it proved difficult as they were high-voltage lines, however, we made the power authority understand the problem and then worked together to prevent another fatal or serious crash in that location.

Planning for road changes

Any solution will require money. There are costs that need to be identified and planned for. But until you have the funds, be confident that you have identified the problem, made a case for corrective action, have a holding strategy, and know how you¡¯ll spend wisely.