Sunday, 21 January 2018

Inshes Overbridge – Width Reallocation

 View this blog as a pdf 


The Inshes Overbridge carries Culloden Road (B9006) over the A9. It is not far from Raigmore Hospital, Beechwood, Inshes Retail Park, and Inverness Campus. It has a fairly even gradient so that many people that use it may not realise that they are crossing a bridge.

It is seen as a pinch point between two major road junctions: Inshes Roundabout and the junction to the east with slip-roads to and from the A9.

In the longer term (by 2026), Transport Scotland intends to widen the Inshes Overbridge to accommodate a 4-lane carriageway and a new desirable minimum NMU facility.

This document relates to the Highland Council’s current project, the Inshes Overbridge - Carriageway Widening scheme *, which is an immediate temporary measure intended to alleviate traffic congestion into Inverness town centre.

* It might equally well be named
The Inshes Overbridge - Cycleway Narrowing scheme.

Currently there is a shared 2-way cycle track on the north side of the road. To the east of the overbridge and crossing it, there is no footway of any kind on the south side of the road.


Width will be be reallocated from the 2-way shared cycleway to enable the carriageway to be increased from 2-way to 3-lane (2 heading into town, 1 heading out).

The resulting narrowing of the cycleway will render it sub-standard for its purpose.

This will be mitigated by two main measures:

  • the erection of two ‘Share and Care’ signs.
  • the identification of an alternative route: Inverness Campus, Golden Bridge, Raigmore, King Duncan’s Road, Millburn Road, Eastgate.

Overbridge Details

Detailed proposals have not been published but the width of the overbridge (13.3m between the parapets) is obviously a fixed constraint. The proposed three-lane carriageway will occupy a width of 9.1m (3.1m+2.9m+3.1m) from kerb to kerb.The length of the overbridge is about 25m.

This arrangement will be achieved by reallocating 0.5m of width from the cycleway to the carriageway.

Impact on Cycleway

The RSA Report refers to Transport Scotland’s document Cycling by Design. (The section on Width Requirements for Cycleways is 6.1.4 starting from page 62.)

It recommends a Desirable Width of 3.0m and an Absolute Minimum of 2.0m. The current full width is about 3m but varies along the route.

Section 6.1.5 lists additional clearances. The two that apply for the overbridge:

  • 0.5m for a continuous feature >1.2m or a bridge parapet of any height
  • 0.5m for being adjacent to a live carriageway

Thus the Effective Width of the current cycleway is reduced to the Absolute Minimum of 2m. It (just) satisfies the guidance.

The proposal to reallocate 0.5m from the cycleway to the carriageway will reduce the Effective Width to 1.5m.

There is a note in the guidance saying that, with low flows, a width of 1.5m may be considered over short distances where no alternative is available.

This is open to interpretation. What is a short distance?
It seems reasonable that a short distance occurs around a local obstruction such as a lighting column or a data cabinet. Cyclists and pedestrians can see each other and negotiate past these.

Is the bridge length of about 25m to be considered short? (It might take a cyclist 5 seconds or a pedestrian 15 seconds to travel that distance.)

In addition, there are two separate lighting columns intruding 0.4m into the edge of the cycleway. These are local obstructions and briefly reduce the Effective Width below the Absolute Minimum of 2m (but above 1.5m) thus conforming to the guidance. Reallocating 0.5m from the cycleway will reduce the Effective Width here to about 1.25m which is well below even the exceptional Absolute Minimum of 1.5m.

The claim that “no alternative is available” is difficult to justify when the alternative already exists and will be removed by the new road layout.

Reference Documents

17 Dec 2017  [14 pages]
Stage 1 & 2 Road Safety Audit Report (RSA)
Produced by Wylie:Lodge Road Safety Consultants

for The Highland Council

13 Dec 2017  [21 pages]
Cycle Audit
Produced by The Highland Council

 [HCC - 21 Jan 2018 - Comments welcome]


  1. The alternative route is better than the current NCN routes. But it is of no benefit to daily commuters (walking or cycling). If it was, they would be using the alternative already.

  2. I would be interested to know by how much traffic and congestion at the Inshes has increased since the opening of the West Link, and if this is driving the need to widen the bridge for motorised traffic. As far as I'm aware, there was never any official HC acknowledgement that the Inshes roundabout would be impacted by the opening, although this was obvious to everyone else.
    Irrespective of that, provided there is a physical barrier between the cars and active travel users (ie not just a kerb, but a metal crash barrier (eg like what separates the cyclists over the Kessock Bridge), I would be happy with that.

  3. A standalone pedestrian/cycle bridge OUTSIDE the existing parapet would allow the whole of the existing width to be re-allocated. A lightweight single span bridge could be dropped into place over the A9 carraigeway, and could feed into the desire line which is "over the bridge and turn left towards the college".

  4. I'm trying to be objective but must agree with Jem that a cycle/walk bridge is the natural solution. Just a simple structure. Not anything as heavy as the Golden Bridge. [BMK]

  5. I like the idea of a standalone cyclist/walker only bridge alongside. Is there a way for individuals to make objections direct to the Council?

    1. I've already submitted an reasoned view on behalf of HCC saying that reducing the cycleway width is unacceptable. I'll check with the Council how they would like to receive comments and post a response here.

  6. That's a route I use to commute and pedestrian/cyclist conflict/congestion is already a consideration with the existing width. It must be one of the busier non-motorised routes in the town and I guess folk are walking/cycling an above average distance too. Whats' the best method to make views known? Councillor's?

  7. This is also a popular route with visitors in the summer time. I know it used by Lands End to John O'Groats cyclists laden with panniers (wider loads) and also day trippers to Culloden Battlefield, Clava Cairns etc. Any degradation of our already piecemeal cycling infrastructure would be a short-sighted act of self harm. Perhaps we could engage with the local authority's risk assessment?

  8. This is an email I sent to The Highland Council today:

    I'm fully aware of the A9/A96 Inshes to Smithton scheme being conducted by Transport Scotland.
    But I'm at a bit of a loss concerning this Overbridge Carriageway Widening scheme by The Highland Council.

    On behalf of HCC, I strongly welcome that we have been informed.
    But I'm not sure of the status of this communication.
    Are we being formally consulted? Or will there be a formal consultation later?

    Some HCC Members have asked me how they should raise objections / concerns.
    Whereas I'm pleased to channel Member's views I don't want to become a gate-keeper.
    How should individuals contact The Highland Council about this?

    I'd welcome guidance on the procedure. [BMK]

  9. For what it's worth there was a planning guidance doc NPPG 17 which related to planning for transport. It's a bit old may even be pre Holyrood! However it gives a transport hierarchy to be applied when considering developments. This is - at the top Pedestrians, then cyclists followed by commercial vehicles with private motor transport at the rear. It appears that THC are reading this upside down. This temporary measure is going to discourage active travel and thus reverse public policy for an unspecified period. It would be worth contacting Neil MacRae at Hitrans to see if they have any more positive ideas than THC. Personally I think the separate cantilvered or bolt on cycle walkway seems like a win win win solution. - much pleasanter for active travellers, allows extra lane and surely cheaper. The last factor may be the most attractive one to THC/Transport Scotland. -

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  11. Pretty dispiriting to be hearing of this plan. A backwards step for sure.

  12. Have any measures been taken to reduce the number of motorised vehicles using this bridge by improving public transport? Continuing to encourage growth in private motorised transport is an extravagance we can no longer afford.