TfL's Guiding Standards on the Design of Cycle Lanes and how they have been applied to the A105

on Friday, 08 December 2017. Posted in N21 Community

Tfl London Cycling Design Standard: The Six Guiding Design Principles & How They Are Applied on the A105 has been prepared by retired civil engineer Peter Johns, who has used his experience to point out scores of failings to the scheme; including the flooding risks on Winchmore Hill Broadway and opposite the Waitrose/former Green Dragon. 


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Introduction


The Tfl London Cycle Design Standards is comprised of eight chapters. In addition Tfl have also published other guidance such as Pedestrian Comfort, Bus Stops and Kerbside Loading but LBE do not refer to these in answering a Freedom of Information request to name design guidance used on the A105 project. In fact quite the opposite. In the case of kerbside loading. Not only are Tfl recommendations not followed, but legal requirements have been circumvented by claiming that the whole project has "experimental status" and LBE is not therefore required to follow legal procedures when making changes to delivery bays.

 

CHAPTER 1 Design requirements 

CHAPTER 2 Tools and techniques   

CHAPTER 3 Cycle-friendly streets and spaces    

CHAPTER 4 Cycle lanes and tracks      

CHAPTER 5 Junctions and crossings

CHAPTER 6 Signs and markings

CHAPTER 7 Construction

CHAPTER 8 Cycle parking

 

 

Clause 1.1.5 in Chapter 1 establishes six desirable design outcomes. These are the guiding principles:

 

Safety

It is stated that "Good infrastructure should help to make cycling safer and address negative perceptions about safety, particularly when it comes to moving through junctions."


There are problems at junctions. Give way lines for vehicles are set too far back making it impossible to ensure, from the give way line, that it is safe to enter the junction. Moving forward to a point where sight lines are good makes the vehicle block the cycle track/lane. Priority at junctions is not clear as there is no signage. The recommendation that a cycle lane/track be set back from the main carriageway at a junction to ensure that the above does not happen has been found to be impossible because of lack of space.

 

Pedestrians are also more at risk with the removal of centre road refuges plus the increase in number of lanes. Instead of the previous one lane at a time, pedestrians must now often cross a four lane highway in a single movement. This manoeuvre has also been made more dangerous by granite setts and orcas being installed in such a way as to provide trip hazards. See section on attractiveness below for more details.

 

Low level kerbs without bollards also constitute a hazard to all road users. These will be especially dangerous at night and in bad weather where poor visibility makes these obstructions almost invisible and after heavy snowfall they may be completely hidden, as shown here, after the first snowfall of the winter on 10 December 2017.

 

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SPOT THE ORCAS

 

It is also stated "Space for cycling is important but a narrow advisory cycle lane next to a narrow general traffic lane and guard-rail at a busy junction is not an acceptable offer for cyclists". Throughout the route, due to lack of space, vehicle lanes are made 400mm narrower than the recommended minimum and cycle tracks/lanes are also narrower than the recommended minimum of 2m. And in some places is as narrow as 1.2m.

 

Moreover, in many places the width of remaining footway has been severely reduced below recommended levels in order to make space for the cycle tracks/lanes. Pedestrian safety in crossing the road has become seriously compromised by the removal of central road refuges. Before these works the pedestrian could cross a two lane road one lane at a time. Now the pedestrian must cross four traffic lanes in one go.

 

The safety of movement of the blind has also been severely impaired by the removal of raised kerbing. Not only is this unsafe, it is, we believe, illegal.

 

In the Tfl Road Safety Audit Stage 1 for this project 75% of road safety concerns identified by the auditor have been rejected by LBE and its designers. The frequency of accidents on the A105 has increased as a result.

 

Directness

It is stated that "Routes must be logical and continuous, without obstacles, delays and diversions, and planned holistically as part of a network".

 

This has not been achieved. Although it is recognised that the A105 project is one early part in establishing the network, there are too many convoluted routes especially at major jjunctions. There are too many routes for both pedestrians and cyclists that it is very unlikely that they will be followed. See figs 9 & 10 in the coherence section below.

 

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 Fig. 1. Showing the pedestrian route to and from the Bus Stop as set out in tactile paving (solid red)

and the Desire Line for pedestrians to and from The Broadway (dotted red).

 

At the other end of The Broadway directness is similarly lacking. Pedestrians walking north along the western side of Green Lanes must turn right and cross the cycle track whilst looking behind themselves to check that there is not a cyclist coming. They walk about 20m. And then must turn left to cross the cycle track again in order to reach Station Road. Cyclists also must suffer a detour in order to approach this road junction.

 

On the eastern side of The Broadway a pedestrian walking north with a push chair or a disabled person in a wheel chair or on a mobility scooter has problems because there is no dropped kerb to allow the crossing of Fords Grove. Neither is there a pedestrian phase at the traffic lights even though one has been provided for cyclists. It is also stated that "Cyclists often choose to stay on carriageway rather than take fragmented routes with built-in delay".

 

We agree but now this is less safe because of the extremely narrow vehicle lanes. Also the ill thought out phasing of traffic lights, such as the one at the Sainsburys junction, results in cyclists leaving the cycle lane and joining the vehicle lane to avoid unnecessary hold up.

 

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  Fig. 2. The Traffic Lights at the Sainsburys Junction at Traffic Lane at Green but with the adjacent Cycle Lane Held at Stop.

 

Comfort

It is stated that "Riding surfaces for cycling, and transitions from one area to another, should be fit for purpose, smooth, well constructed and well maintained."


This has often not been achieved especially at the entry and exit to raised bus boarders Workmanship standards are, most politely described as, 'variable' with manhole covers and drainage gully gratings often set in at the incorrect level making the ride in the cycle lane far from smooth. See Figs 3, 4, 5, 6 & 8

 

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For poor maintenance see the section on attractiveness below.

 

It also stated that "Uncomfortable transitions between on-and off carriageway facilities are best avoided, particularly at locations where conflict with other road users is more likely."


At many raised bus boarders, poor workmanship has resulted in this recommendation not being achieved. See Figs 7, 9 & 10 above show examples of badly constructed ramps.

 

Coherence

It is stated that "Infrastructure should be legible, intuitive, consistent, joined-up and inclusive. It should be usable and understandable by all users."


Evidence is that this is not happening on the A105. Cyclists ride both ways down one way cycle track/lanes, pedestrians ignore the tactile paving and follow desire lines and the blind complain that the absence of raised kerbs makes mobility difficult are just three examples of this.

 

Even for able bodied pedestrians, cyclists and motorists the desire to reduce street clutter to a minimum but this has been taken to the point where the total lack of signs results in much confusion existing as to who or what has priority or right of way where the various groups come into conflict.

 

Tactile paving is both not understood and lacking the force of law. Traffic policing is at an all time low and because of fiscal stringency is facing further cuts. Many cyclists are now using this to their advantage by their anarchic approach and lock of consideration to other road users.

 

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Fig. 11. A cyclist riding the wrong way along a cycle lane.

 

It is also stated that "Neither cyclists nor pedestrians benefit from unintuitive arrangements that put cyclists in unexpected places away from the carriageway".

We agree.

 

Attractiveness

It is stated that "Infrastructure should not be ugly or add unnecessarily to street clutter. Well designed cycling infrastructure should enhance the urban realm. Sometimes well-intentioned signs and markings for cycling are not only difficult and uncomfortable to use, but are also unattractive additions to the streetscape."

We agree. However the lack of signage is causing cyclists to ride the wrong way along cycle tracks/lanes and causing confusion and conflict at road junctions and the raised bus boarders.

 

Maintenance

Items such as street cleaning have become much more complicated and therefore more expensive as a result. mechanical street cleaning is almost impossible where kerbing suddenly changes direction. Cycle lanes are also often not swept resulting in broken glass causing punctures and many cyclists, as a result choosing to continue to use the now narrower vehicle lanes.

 

The granite sett borders to cycle track have often been laid with the sett protruding more than 20mm above the surrounding pointing. This results in cigarette ends and other debris collecting between the setts and being almost impossible to clean by traditional sweeping. These raised setts also constitute trip hazard

 

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Figure 12 is taken from a catalogue and shows how granite setts should be laid.

The other figures are of photos of the cycle track buffer strips taken along the A105.

Figure 13 shows the setts laid well.

Figures 14 & 15 show setts laid to a variable standard

Figures 16, 17 & 18 are from areas where the setts have been laid to an unacceptable standard.

 

As laid, these setts constitute trip hazards as defined in LoHAC contract conditions. The very uneven surface also harbours rubbish and Figure 19 was from an area where this has happened.

 

Adaptability

It is stated that "Cycling infrastructure should be designed to accommodate users of all types of cycle, and an increasing numbers of users over time."

 

Because of the extreme narrowness of cycle lanes/tracks in many places this is now impossible. It is also stated that "Where streets have been engineered primarily for use by motor vehicles, it is difficult to make infrastructure for cycling that is legible and adaptable."


We agree, and the lamentable efforts of LBE and its designers and contractors bears witness to this statement. Instead of abandoning the A105 for this type of modification and looked for alternative routes, political ideology has rode roughshod over good engineering practice.

 

In conclusion


The result is a road that no longer is safe, attractive or easily understood. The desirable design outcomes, as set out in the London Cycling Design Standards are sensible standards necessary for the safe and comfortable functioning of the A105. The failure by the designers, the contractor and ultimately the London Borough of Enfield to adhere to these standards is a direct result of the wrong route being chosen on which to attempt to build cycle lanes. Major corrections need to be urgently made to bring Green Lanes back to an acceptable standard.

 

 LINK TO TfL REPORT


The Author of this analysis Peter Johns is is a former Chartered Engineer, Member of the Institution of Civil Engineers and Member of the Institution of Structural Engineers. He has a BSc Degree in Civil Engineering from the University of Birmingham.

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