St Peter's Hill without a kerb
Walking down St Peter's Hill today, the first thing a sighted visitor notices is the flatness. There is no step at the road edge, no raised lip to catch a toe or a pushchair wheel — the surface runs uninterrupted from shopfront to shopfront, broken only by a shift in material underfoot. Smooth York stone flags cover the pedestrian zone; granite setts take over where vehicles are expected to move. The contrast is clean, almost continental in feel, and the overall effect is of a town centre given room to breathe.
South Kesteven District Council delivered the scheme as part of a broader public realm improvement — the stated aims were to calm traffic, lift the street's appearance, and make the area more attractive to visitors and shoppers. Those are legitimate design goals, and the material palette achieves them visibly. But the same flush surface that makes St Peter's Hill legible to the eye removes a feature that, for someone navigating without sight, was never aesthetic. The kerb is gone, and the granite setts that replaced it do not do what the kerb did.
The four things a kerb tells you
A standard UK footway kerb sits between 100 and 125 mm above the carriageway — roughly the height of a thick paperback standing on its spine. That height matters because a white cane, swept in an arc ahead, drops when it clears the edge. Orientation and mobility research is consistent on this point: an upstand of around 40 mm or more registers as a hard boundary, stopping the user's forward movement. The kerb is, in that sense, a physical sentence boundary — the body is halted before the carriageway begins.
A kerb does not only mark a point, though. It runs continuously along an entire street frontage, giving a blind pedestrian a linear reference to track between formal crossing points. This is different in kind from a blister pad at a specific crossing: the kerb tells you not just where to cross, but where you stand at any moment along the pavement.
Two further cues reinforce these first two. When a cane tip or footstep moves from smooth flag to tarmac or rough sett, the sound shifts — an acoustic change that confirms a transition the height differential has already announced. And it is that height differential which provides what no texture change can: a physical halt. The cane drops; the foot meets resistance. Texture variation underfoot is detectable by cane sweep, but it does not arrest forward movement at the road edge.
The result is that a kerb delivers four simultaneous signals — height, linearity, sound, and physical arrest — each through a different sensory channel. Remove the kerb, and all four go at once.
What granite setts can and cannot do
Granite setts are not neutral. The surface on St Peter's Hill is rougher underfoot than the York stone flags, detectable both through the cane tip and through the sole of a shoe — measurably more feedback than a uniform smooth carriageway would provide, and that difference is real.
RNIB's assessment of material palettes of this kind cuts to the limitation directly: the combination 'communicates to the eye, not to the cane.' Visual contrast between pale stone and dark sett is strong — a sighted person reads the boundary immediately. But a cane reads height and resistance, not colour or pattern, and the sett surface offers neither a step nor a linear stop.
The geometry compounds this. In Grantham's scheme, the transition from York stone to granite setts occurs across a zone rather than at a single line. A kerb edge exists at a precise point along the entire street frontage — a cane sweeping laterally meets it within a millimetre of travel. The sett area spreads across a width; there is no single moment at which a cane user can register 'here is the edge.' Navigation by tracking a continuous linear boundary — a technique used by orientation-and-mobility trained pedestrians as their spatial reference between crossings — has no equivalent when the boundary is an area with soft margins.
What the setts achieve, then, is some confirmation of surface change for a pedestrian who is already oriented. What they cannot offer is the unbroken linear reference that told a blind pedestrian where they stood at any point along the street frontage, without depending on a formal crossing to anchor their position.
What the scheme kept — and what it cannot cover
The scheme did retain something. Tactile blister pads — the domed-stud surfaces familiar at pelican and zebra crossings — were kept at Grantham's formal crossing points across St Peter's Hill. That is a genuine provision, not a token one: blister pads give a standardised signal that a controlled crossing is directly ahead.
Blister pads are, however, a hazard warning at a specific point, not a guide along a route. Between two crossing points — say, at the northern and southern ends of St Peter's Hill — a blind pedestrian walking the length of the street has no continuous linear feature to track. Previously, the kerb ran unbroken along that frontage: always there, always locatable from one side, a reference available at any step. In a level-surface scheme, there is none.
The scale of this loss differs from losing a single aid at a crossing. A missing crossing cue is a punctual problem — one point of confusion. Losing the continuous kerb line removes orientation along the entire length of street between crossings. What changes, in practical terms, is how far a person can walk confidently before needing to stop and re-anchor their position — and how they do that re-anchoring at all.
How the design profession and policymakers responded
The design profession's own reckoning arrived later. Hans Monderman, the Dutch traffic engineer whose shared-space theory spread across European towns from the 1990s, conceived the approach as a vehicle-speed tool: remove kerbs, road markings, and signals, and drivers lose the certainty that grants them priority and slow accordingly. Accessibility for non-visual users was not a criterion in that founding framework — shared space was designed to change driver behaviour, and the question of how a blind pedestrian navigates without a kerb line simply was not in the calculus.
Guide Dogs UK's Streets Ahead campaign and RNIB documented what that gap produced in practice: schemes optimised for traffic calming that had never modelled non-visual navigation. The 2018 DfT-commissioned research report formalised the finding — shared space presents specific, unresolved difficulties for disabled people, and local authorities should exercise caution before building new schemes. The practical result was an effective pause on kerb-free development in England.
Grantham's St Peter's Hill scheme predates that inflection point. It belongs to a period when the profession had not yet absorbed these failures, which means it was designed and funded before the access evidence had forced a public reckoning from either central government or the highway engineering community.
The moratorium addresses new proposals. It does not require existing schemes to be reconsidered.
What 'enough' would actually look like
The test is practical: can a blind pedestrian track the full length of St Peter's Hill's frontage without a sighted guide or cane escort? On the current surface, the answer is no — not because the York stone or the granite setts are badly chosen, but because no material palette alone creates a continuous linear physical boundary at a meaningful height. That is the specific gap the scheme leaves open.
One intervention that would change the answer is a continuous linear tactile strip — corduroy hazard paving or similar — running along the full frontage at the point where pedestrian zone meets vehicle movement area. DfT Inclusive Mobility guidance identifies exactly this kind of compensating feature as what level-surface schemes need when the kerb is removed. The honest trade-off is that such a strip introduces a functional seam into a scheme designed for visual coherence. A corduroy line, continuous across the setts, would be precisely the thing the designers took out — restored in a different material, for a different user, cutting across the aesthetic logic the scheme was built around.
Grantham's town centre will be redesigned again. When it is, that tension — the navigation seam a blind pedestrian needs versus the surface continuity a shared space scheme offers everyone else — is the concrete question worth putting in front of whoever specifies the next surface.
- [1] Shared space. https://en.wikipedia.org/?curid=3287020 https://en.wikipedia.org/?curid=3287020
- [2] Tactile paving. https://en.wikipedia.org/?curid=6726259 https://en.wikipedia.org/?curid=6726259
- [3] Seiichi Miyake. https://en.wikipedia.org/?curid=60259737 https://en.wikipedia.org/?curid=60259737