Ashes to Ashes: Hazardous Highways

If you don’t know what ash dieback is, it is worth checking out DEFA’s webpage: This tree disease is going to dramatically change the appearance of our roads and landscapes over the next 10 years.

A question I am often asked is “what are the government doing about ash dieback?!”.

Due to the epidemiology of the disease, it is, unfortunately, nye on impossible to stop it spreading through our ash tree population. Because of this, DEFA have not attempted to start a control programme like they did for Dutch elm disease in the 1990’s. With no real interest in trying to prevent the spread of the disease, DEFA’s main interest relates to its duty of care to keep people safe on its own estate (i.e. in our national glens and forest areas). When ash succumb to this disease they have the potential to become a significant hazard to people and property. The Public Estates and Housing Division of the DoI, who manage a large and varied estate of public buildings and housing stock, also have this burden. Both these Departments of government have a ‘tree management strategy’ in place which sets out how they manage risk from trees, so as long as the policies and procedures set out in these documents are followed, and there is a budget available to undertake the work, risk of harm from diseased ash should be reduced to an acceptable level.

Another significant area of Government that needs to act on ash dieback is the Highways Division of the DoI (‘Highways’). Many of our primary transport routes are lined with trees; many of those trees are ash; many of those trees are going to be in a compromised structural condition in the next 5 years, if they aren’t already.

Private landowners are responsible for trees on their land. If an ash tree in an obviously poor physiological or structural condition were to injure someone on a public highway, the owner of the tree may be found liable if a compensation claim is made against them. Despite there being a number of responsible landowners seeking to prune or remove their compromised ash trees, there are still a substantial number of ash trees to deal with adjacent to our highways. I won’t dwell on the reasons why so many landowners are not dealing appropriately with their trees, as that wasn’t the point of this post and is, perhaps, an article in its own right. The point is that Highways also have a general duty to keep users of our road network safe from foreseeable harm, including taking action when there is an obviously hazardous tree adjacent to the highway. For this reason, the Highways Act 1986 allows Highways to order landowners to deal with such trees and, if the landowner fails to comply, allows Highways to enter on to the land to undertake the work and reclaim the costs.

Despite having these powers, however, the DoI have told Manx Roots (email correspondence, 25th May 2022) that no such notices have been issued for ash trees in the last 3 years, and that very few have ever been issued.  So, if Highways aren’t (yet) making private landowners deal with their ash trees, what are they doing?

Well, we know they are definitely looking at the issue. The results of two preliminary surveys have been published online which aimed to calculate the scale of the problem and the budget needed to tackle it. The conclusion? The disease was present on all routes surveyed, except for the mountain road and coastal roads, and 61% of surveyed ash show significant signs of dieback. Hardly earth-shattering results, but it’s a good starting point for justifying the allocation of budgets and human resources to tackle the issue. The surveys are available here:

Isle of Man Government, Highways and Asset Management – Ash Dieback

So, what’s being done with this information? ‘Ash Dieback Mitigation’ is listed in the government’s budget for the financial year 2022-23 (Pink Book 2022), but £416,000 is a paltry amount when you consider the scale of the problem. Given the costs of undertaking tree work on the highway, with traffic management and a high level of logistical input required, it doesn’t seem like Highways are likely to have the resources to start felling ash on a large scale. Moreover, this funding is only committed for one year; there is no commitment to spend additional funds in future years.

So, how are Highways planning to spend this money? A ‘prior information notice’ (PIN) has just been released on the government’s procurement portal so that Highways can ‘explore the market’ for companies capable of ‘clearance of a large number of trees’. What is a large number? If they can’t afford to deal with all the trees, where will they start? Will they concentrate resources in one area, or spread it out over the whole network? Will direct employment of contractors (under the powers of the Highway Act) be the first course of action, or a last resort?

We are left guessing the answers to these questions because there is currently no published strategy for how they are going to deal with the problem. Is this because one doesn’t exist, or just that they haven’t published it? We’re not sure. There certainly hasn’t been public consultation on a strategy, and Manx Roots haven’t been invited to comment as part of a targeted stakeholder/industry expert consultation.

The answer then, to the question we are often asked – what is government doing about ash dieback? Based on the information currently available, the answer seems to be a not very satisfactory “they’re thinking about doing something”. Even if a detailed plan of how Highways are going to spend the allocated budget does exist, its unlikely to include felling and pruning on a scale that I believe is necessary to prevent a serious accident occurring, because the budget is nowhere near big enough, despite the rhetoric of the recently published PIN.

Some people reading this will be understandably cynical. Somebody who makes money from giving people advice about trees telling you the trees might be dangerous: pull the other one! The fact is, with the extent of dieback that we’re talking about, you don’t need to be an expert to spot the dangerous trees. Most infected ash are obvious, even to a lay person, but only when they take the time to look. In relation specifically to ash dieback, for most roadside situations we would only advise that professional arboricultural services are required for surveying when there’s an element of doubt, or it is a particularly high stakes or complicated situation. There is a wealth of accessible and easy-to-understand information available online about how to spot the symptoms of ash dieback (see link below as a starter). Plus, even if we wanted to, we don’t currently have the capacity to survey the whole road network!

Sadly, due to a lack of action by landowners and the Government, many people working in our industry believe it is a matter of when, not if, someone will be killed or seriously injured by a dangerous tree on our highways. I hope we’re wrong.

For more information about ash dieback, including some great links to information about what to look for, we recommend you visit