Some interesting answers... but many more questions

fact: too many adult pedestrians are killed or experience life-changing injuries on liverpool's roads, and whilst the overall number of collisions is reducing , pedestrian casualties in liverpool have plateaued since 2008.   

So-Mo have been asked to address this challenge.  For this project, we have joined forces with Road Safety Analysis who are providing us with support to analyse the data and will share their not-inconsiderable experience in the field of road safety.  In this blog we learn what the data tells us about where collisions are occurring, who is involved and begin to uncover some potential causes.

 

As described in the previous blog, we’ve set out on a voyage of discovery to understand the challenges faced by adult pedestrians in Liverpool. We’ve completed several weeks’ worth of analysis of the police collision data and are now building up a clearer picture of what is happening. So, what have we discovered?

To begin with, adult pedestrian casualties are a national challenge. In Great Britain each year, over 4,000 adult pedestrians are killed or seriously injured (KSI) and this has changed very little in recent years in comparison to other road users. Vehicle occupants (such as car, goods and bus drivers and passengers) have seen general downward trends in KSI casualties since 2007, whilst motorcycle riders and pillion passengers and adult pedestrians fell initially and have plateaued since 2009/2010. Meanwhile, cycle KSI casualties have increased over the last decade, especially since 2011. Thankfully, child pedestrian KSI casualties have reduced year on year since 2007.

 

chart 1.jpg

Some of these trends are simple to explain: there have been increases in cycle usage, which may be contributing to the higher numbers of cycle casualties; conversely there are continual improvements in in-vehicle safety, ensuring that drivers and passengers are less likely to sustain serious injury in the event of a collision. Anecdotally, it is believed that children are walking far less than previously (so lower exposure may be contributing to the general downward trend) but reductions in vehicle speeds and road safety education are also likely to be playing a part. But other vulnerable road users, such as motorcyclists and adult pedestrians, have not experienced technological or exposure changes which would reduce their risk and therefore this is why we delved into the issues facing the latter group to see what could make their journeys safer.

The analysis of adult pedestrians injured in Liverpool was not carried out in isolation. It was decided that using ‘similar’ local authorities to Liverpool would put the findings into context. Is Liverpool ‘normal’?! Two sets of similar authorities were identified: there are those who have a similar road network to Liverpool, and those who have similar types of residents.

Whilst not initially obvious, Bournemouth, Southend-on-Sea and Wolverhampton all have similar road networks to Liverpool! These were selected because they have a similar network density to Liverpool (which is determined by dividing the total length of roads in the authority by the total area of the authority); they also have no roads which belong to the Strategic Road Network (SRN), managed by Highways England and which includes motorways and major dual carriageways; they all have similar traffic flow, and have a similar population density. All of these factors combined suggest that these three other authorities face similar demands on their network to Liverpool and therefore if the collision findings are similar in Liverpool to these other authorities, then we might be able to infer that there is something about the network which is leading to increased risk.

 We also wanted to understand if the people who use Liverpool’s roads are contributing to the increased risk. As explained in the previous blog, systems like Mosaic Public Sector can be used to understand the backgrounds of individuals involved in collisions. There were four authorities which were selected as comparator authorities because the Mosaic Groups are represented in similar proportions to Liverpool. Described as socio-demographic comparators, Kingston-upon-Hull, Manchester, Sheffield and Nottingham, are all used to see if the people involved in the collisions are the key to reducing risk – if Liverpool is similar to the socio-demographic comparators, then it could be that it is more about people than road network.

So, what have we found?

It seems that the reason why adult pedestrian risk is so high in Liverpool is that there is a combination of network and socio-economic issues.

The network definitely appears to be playing a part in adult pedestrian collisions. In total, 20% of the casualties were on dual carriageways at the time of their collision, which is twice the percentage for both sets of similar authorities. This is partly because Liverpool has more dual carriageway roads than elsewhere and two major routes heading in and out of the city (the A57 and the A59) feature prominently. What we need to find out next is how these routes are used by both drivers and pedestrians and what the crossing facilities are to enable people to walk across dual carriageways.

Map 1.jpg

 

Crossing facilities are important. Over 50% of the adult pedestrians injured in Liverpool were in the process of crossing the road but were not at a physical crossing. Is this because there were no crossing facilities available (or they were in the ‘wrong’ place) or because pedestrians were choosing not to use them? We need to do some visits to cluster sites of collisions to find out.

Which brings us to behaviours. There’s a peak in the number of adult pedestrians injured between 5pm and 6pm in Liverpool and this is also the case in the similar authorities. It is not at all surprising that risk is heightened at commuter times when there are more vehicles on the road and more people walking home from work.

What is more interesting is that 40% of adult pedestrians in Liverpool were injured between 6pm and 6am and this is quite a lot higher than for the similar network authorities (but not different to those areas with residents from similar backgrounds). There were peaks at weekends as well, and combined with the city centre clusters, there looks like there are links to the night-time economy. Over 20% of the adult pedestrian casualties who were in police-attended injury collisions in Liverpool were thought to be impaired by alcohol – reckless and drunken behaviour, poorer lighting conditions and different traffic demands are likely to be influencing risk at night. Observations of crossing actions and general pedestrian behaviour, as well as viewing the way vehicles use the roads at night, will help us to understand the conflicts a lot better.

There’s a lot more that has emerged from the data which will be included in the final report (we don’t want to give away all the information away now and we don’t also want to write really lengthy blogs!). But what we have got is a good insight into what is happening in Liverpool and some clear direction on what information we need to collect next. Watch this space as we start to really define the areas we ought to focus on, both geographically and behaviourally…

 

BACK TO BLOG

Nicola Wass