Every subject has its jargon and cycle campaigners have to come to terms with the traffic planners’ terminology. Some of the terms are here becase of their obscurity and some because of their controversy.
Advisory cycle lane
A cycle lane which is present for guidance only. Unlike a mandatory cycle lane, vehicles can park in it and drive in it, so its only effect is to imply to motorists that they should keep out of it. It is marked out on the road with dashed lines, sometimes surfaced in red (in Cambridge especially across junctions, and in London and other parts of the UK sometimes green), and signposted with a white bicycle on a blue rectangular background.
AJC; Area Joint Committee
Committees which make local decisions on transport matters in Cambridgeshire. There is one for each participating district council area and they are formed from councillors from both the Cambridgeshire County Council which is the transport authority, and the relevant district council (Cambridge City Council in the City, South Cambridgeshire District Council around it). The committees can be overruled by the County Council.
Advanced stop line; Forward stop line; Forward stop box; Cycle box
a box marked out on the road at traffic signals, often surfaced in red, sometimes with a cycle lane leading into it. Placed in front of the line where motor traffic should (but often doesn’t) stop on red, usually across all the traffic lanes, but sometimes just one, the idea is to allow motorists to see cyclists better (without the box, they would be to the left of the vehicle). In particular this avoids the situation where a driver turns left across the path of a cyclist who is going straight on. They also have the added advantage of giving cyclists a fairer use of the time when lights are on green.
An extension of the kerbed pavement area or a planter into the road which is used to artificially narrow it for the purposes of traffic calming. Cyclists are concerned about these because they form pinch points which put them at risk. Attempts are sometimes made to provide cycle bypasses, but these are rarely satisfactory. Only one kind really suits cyclists (not a build-out at all really): this is where a single lane is formed centrally by a pair of traffic islands which cyclists can pass on the near-side; even then the by-pases must be adequately wide to accommodate wide trailers and tricycles, and sufficiently-long mandatory cycle lanes are required on the approaches to prevent cars parking up to the islands and blocking the by-passes. Reasonable examples can be found in Radegund Road, though the approach lanes are rather short leading to swerving around parked cars.
Bus gate; Rising bollards
A location where only buses, cycles and taxis are allowed to pass through. These are two kinds:
- Those controlled by traffic signals (traffic lights) at the end of bus lanes. Buses activate the lights from some distance away. In theory this gives them priority over the adjacent traffic which is stopped by a red light. Nearly all these gates have cycle filters which allow cyclists to pass through even on red. In one instance (on Newmarket Road) this is even the case where the gate is integrated into a junction. Obaining these filters was a major achievement of Cambridge Cycling Campaign.
- Those controlled by rising bollards, that is poles in the road which physically stop cars getting through but which are automatically lowered for buses (and taxis). Cyclists can get through these (at their peril) but all are also provided with cycle bypasses alongside. Examples are found in Emmanuel Road, Bridge Street and Silver Street.
Both types are activated by a device called a ‘transponder’ mounted underneath permitted vehicles, which is detected by a sensor in the road.
Cycle bridge at the station; Carter Bridge
The long red and blue cycle bridge at Cambridge railway station between Devonshire Road and Rustat road is officially known as the Carter Bridge. We prefer to call it the ‘cycle bridge at the station’ because Tony Carter, the politician after whom it was named, was primarily responsible for the iniquitous bike bans in the centre of Cambridge, and we resent a cycle facility being named after someone who did cyclists such a disservice.
Contraflow cycleway; Contraflow lane
A mandatory cycle lane, that is for the exclusive use of cyclists, which allows cyclists to travel in the opposite direction to the other traffic in what would otherwise be one-way street.
Large tiles, usually a beige colour, with a long, shallow, parallel ribbed texture set into the start and end of shared-use pavements which aid blind and partially sighted people to distinguish when cycles are likely to be present on a shared-use footway (pavement). Where the path is unsegregated, the slabs are placed so the ribbed texture is aligned across the path so a cane would smoothly pass across it, but on the cycle side of a segregated shared-use path the ribs are oriented in the other direction so that a cane would rattle when drawn across them, thereby alerting the user that they should use the other side. See also Tactile paving.
Cambridgeshire County Council
Cambridgeshire County Council is the local highway authority and local transport authority for our area. That is, it is in charge of transport matters including traffic management and road safety. Elected every four years, decisions are taken by a cabinet, and specifically a cabinet member with responsibility for transport matters, supported by a large team of paid officers. In practice, many decisions are greatly influenced by the professional officers. In some districts, including Cambridge and South Cambridgeshire, area committees (area joint committees) bring groups of councillors together from the County Council and the relevant district (Cambridge City Council, South Cambridgeshire District Council) to make detailed decisions on traffic matters, including most issues affecting cyclists.
The County Council is not the planning authority. Decisions on planning are made by the district council, and these often have major imlications for transport. Cycle parking standards in new developments also therefore falls to the district council, though public street parking is usually provided by the County Council. Cambridge City Council also runs the city’s car parks.
The County Council is also not directly responsible for trunk roads, that is those signed in yellow on a green background. These are the responsibility of the Highways Agency, a quango related to the Department for Transport (DfT). However, in practice, much trunk road work is delegated to the County Council.
Crash; Accident; Collision
We generally prefer the use of ‘crash’ or ‘collision’ to describe an event where road users unintentionally come together resulting in damage or injury. ‘Accident’ has the connotation that it was something that just happened, could not have been avoided, which is rarely the case. See also Personal Injury Accidents.
A designated point whee pedestrians and cycles may cross the road, often controlled in some way.Examples are:
- zebra crossing, where road markings indicate vehicles must give way
- pelican crossing, controlled by traffic signals
- toucan crossing, ditto, but which cycles may also use
See also multi-stage crossings.
Cycle filter (of traffic lights)
A green bicycle on a set of traffic signals (traffic lights) which allows bicycles to proceed when other traffic in the same lane is halted. These has been used exclusively in Cambridge at the ends of bus lanes where the signals are controlled by buses. In once case (on Newmarket Road) the exception is part of a junction and allows cyclists through even though traffic is turning into the same path, thogh there is a narrow lane separation.
A lane marked with white paint on the road surface and blue and white signs intended for the use of cyclists. There are two kinds:
- mandatory cycle lanes, which are for the exclusive use of cyclists and marked with a solid line, and
- advisory cycle lanes, which are for guidance only.
Cycle parking; cycle parking standards
Cycle theft is a major problem in Cambridge. Better and more cycle parking has been one of the big achievements of Cambridge Cycling Campaign. Nevertheless, there is still much less than needed.
Street parking is usually in the form of the ‘Sheffield Rack’, or some variant of it. This is a hoop of metal tubing which a cycle an be securely locked to. Whatever the variant it is important that
- cycles are properly supported (usually needing two points of support);
- cycles can be securely locked to it (ideally through both frame and front wheel); and
- there is sufficient room around and between stands to manouvre: typically this means allowing 1.5m2per space (3m2per stand).
Older cycle parking is still sometimes found: concrete blocks with slots for wheels are notorious wheel-benders and offer no security. Bikes parked in these will not usually be insured. V-grip stands which grip the front wheel only can also bend wheels, are usually much too close together, and offer minimal security.
Street parking is usually provided by the highway authority, that is Cambridgeshire County Council. In new developments Cambridge City Council, the lanning authority, has laid out a set of standards for cycle parking (and car parking) that shold be provided. However, it does appear that large developments are treated highly leniently with respect to these standards, in some cases no cycle parking at all being required even when the standards say there should be dozens or even hundreds of spaces – for example, despite representations, the redevelopment at Bradwell’s Court in the City Centre hasno cycle parking at all provided, at the same time as street parking is being reduced in the immediate area.
A purpose-built or specifically-designated route for the use of cyclists which is separate from the road (often alongside a road, but not necessarily). These include cycle tracks and both segregated and unsegregated shared-use pavements.
Strictly speaking, a surfaced carriageway purpose-built for use by cyclists usually parallel to a road but separated from both the road and the footway (pavement) either by a difference in level or a verge. For example, the facility on the west side of Barnwell Road is a cycle track. However they are rare in Cambridge (indeed everywhere). Therefore, we often use the term to include purpose built segregated shared-use facilities where the cycle track is separated from the footway only by a white line.
A generic term for purpose-built or specifically-designated routes for cyclists. These include cycle lanes and cycle paths which in turn include cycle tracks and both segregated and unsegregated shared-use pavements.
DfT; Department for Transport
The Government ministry responsible for transport in the UK. They draw up the rules for signage and standards, and allocate funding to local authorities. They are also responsible through a quango called the Highways Agency for trunk roads (that is a defined set of primary roads, those signposted in green with yellow lettering); most other roads including most of the ones we need to deal with as cyclists are the responsibility of the County Council.
Filter (of traffic lights); slip light
A green arrow on a set of traffic signals (traffic lights) which allows one lane of trafic to proceed in the direction of the arrow while other traffic remains stopped. In some cases in Cambridge there are also cycle filters to allow cyclists to pass through an otherwise red signal.
Flush kerb; Drop kerb, dropped kerb, flush dropped kerb
Where cyclists are on a path higher than the adjacent road surface, the kerb must be dropped, that is ramped downwards, at points where the path joins a road. For comfort these should be flush kerbs, that is flush or level with the road surface. Often they are not due to incompetence. Even on good examples, there is nearly always a slight difference in level to try to help water drain properly and not pool in the ramped area, but the difference is often much too great. Also, these are very often found at the mouth of a junction where the kerb is curved so they meet the road at an awkward angle.
Ordinary mortals say ‘pavement’, but traffic engineers call the path alongside roads set aside for pedestrians a ‘footway’. Increasingly in Cambridge footways are shared-use, that is cyclists are allowed to use them shared with pedestrians.
Where two roads meet – or a cycleway meets a road or another cycleway – one of the roads has priority over the other. Traffic on the non-priority road must give way to the other, so as a noun, a give-way is such a location. This is marked by a pair of parallel dashed lines across the road (or cycleway) and a triangle with its apex pointed towards the traffic that must give way. On roads (not usually cycleways) there is also a give-way sign, a red triangle with apex downwards, containing the words GIVE WAY on a white background.
Global Positioning System (GPS)
A system of earth satellites and electronic receiving equipment by which the user of the receiver can pinpoint their location very accurately, usually to within a few metres. Receivers are now relatively cheap and portable so can be used on a bike, but are not accurate enough, for example, to guide a bus along a guideway.
Gradient; slope, ramp
How steep a road or path is. Measured as 1 in N, that is a 1 unit height change for each N units forward, or its percentage, the ratio of the distance forward to the height change over that distance multiplied by 100.
So in the first case the smaller the number the steeper it is, and in percentage terms the larger the number the steeper it is. 1 in 20 (5%) is generally considered to be about the steepest that it is reasonable to build cycle facilities (ramps leading onto bridges etc.), and even then many cyclists struggle and have to dismount.
The cycle bridge at the station is 1 in 20 (5%) on one side and 1 in 18 (5.5%) on the other. 1 in 7 (14%) is steep even for cars and 1 in 3 (33%) is steep even to walk. The Wrynose Pass in the Lake District is one of the steepest public roads in the UK at 1 in 3.
Railings, usually metal about 1.2 metres high, but sometimes lower wooden barriers, alongside a road or around a traffic island which prevent pedestrians stepping into the road or crossing at that point. These can cause problems for cyclists on the road who cannot escape when a large vehicle comes close, and on the pavement (where permitted) as they are always planted some way in from the kerb and narrow substantially what is often already a narrows facility.
Guided bus; Busway; Guided busway; Bus guideway
A guided bus scheme is likely to be built north and south of Cambridge. Buses are adapted on one of two ways:
- they have small wheels mounted horizontally on sprung arms at the four corners of the bus which allow the bus to travel without steering in a shallow concrete trough called the guideway
- or they have a light under the bus and a sensor, which can pick reflections off a line marked on the guideway surface to keep the bus traveling accurately in a straight line. In this case the guideway need only be two strips of tarmac a bit wider than each of the tyres.
These systems allow the bus to travel faster, on its own exclusive road, but means the buses can also leave the guideway to travel on the ordinary roads, for example in the City where building a guideway is not practicable. The Cambridge scheme is currently proposing the former type of guidance system. This makes it hard to cross, especially with a bike. The scheme does, however, provide for a cycleway along its length, albeit possibly not tarmac surfaced.
Gully; Drain; Drain cover; curved gully
The heavy metal grid about 50 x 30 cm installed at the road edge to allow surface water to flush into the drains beneath. Generally the gratings on these gullies should be at right angles to the kerb so that cyclists narrow wheels cannot get stuck in them. Some, however are at an angle and/or have pointed tops which can be slippery. Many are also sunk deeply into the road surface, and while most cyclists should not be cycling this close to the kerb, they can be a particular problem for tricycle and trailers.
Hump; road hump; sleeping policeman
An artifically introduced mound in the road intended to slow traffic. Depending on the profile, these can be extremely uncomfortable to cycle over. The best kind are sinusoidal in profile. However other kinds of traffic calming are often better still, for example speed cushions.
Island; traffic island; pedestrian refuge
A raised area in the middle of a road which separates traffic streams. Usually built to kerb height, and with illuminated bollards indicating their presence to traffic. Often they are provided togive pedestrians the cahance to cross busy streams of traffic in stages. Sometimes guard railings are used on the island to encourage pedestrians to pause on the island. Also used to slow traffic as part of a traffic calming scheme.
These are of especial concern to cyclists because vehicles often will not wait for a cyclist in the narrow section. They try to overtake in the gap and actually acelerate to try to overtake before reaching the island. Cyclists very commonly experience a car passing on the wrong side of the island because they have misjudged the ability to overtake the bike, and realise at the last minute they have nowhere else to go.
KSI; Killed and seriously injured
Injuries sustained in crashes – collectively called Personal Injury Accidents – are graded into three levels of severity: people killed, those which are serious, and not serious. The first two are collectively referred to as Killed and Seriously Injured, or, rather callously, simply as KSI. These are aggregated because the number of such injuries is often (arguably erroneously) used to rank locations to infer their need for safety measures. It is often argued, however, that this is not a good measure because many vulnerable road users will avoid somewhere that is hazardous (or perceived so) and therefore a location in need of change will not show up in the statistics. See also Stats 19.
LAPE; Local Authority Car parking Enforcement; Parking enforcement; Enforcement of car parking
Cambridge has recently taken advantage of a system which allows the County Council to enforce car parking infringements rather than the Police. The Council has contracted this out to private operators. In principle this should help cyclists, as the Police never had the resources to adequately do the job. However, in the new system, the operators cannot currently enforce situations where cars park in a mandatory cycle lane and the Police now refuse to do this enforcement themselves, so actually the position has worsened.
Loading (and unloading) is often permitted where general parking is not. This can sometimes mean in mandatory cycle lane. However,loading restrictions are widely abused – for example deliveries regularly take place in peak hours in the bus/cycle lane on Hills Road near the Co-op. See also Car parking enforcement
London design standards
Transport for London has drawn up a set of standards to which cycle facilities should be built. In the absence of similar standards here in Cambridgeshire, it is useful to be able to refer to such standards elsewhere. Edinburgh also has a set of concise and positive standards.
Loop; Detector loop, Capacitor loop (of traffic signals)
An electrical cable buried in the ground on the approach to traffic signals (traffic lights) which detects traffic instructing the signals to change. Also sometimes used simply to count traffic. While not too bad in Cambridge, many loops are not sensitive enough to detect some cycles, so certain lights will not change when a lightweight bike approaches. Particular examples are the bus gate at the Newmarket Road / Ditton lane junction, and the Lydewode Road approach to the Devonshire Road junction. The latter is particularly regrettable as it is designed for the exclusive use of cycles.
LTP; Local transport plan
The five year proposal for transport priorities and spending drawn up by the transport authority, which in our area is Cambridgeshire County Council, and submitted to the Department for Transport as the basis for allocating funds between areas. DfT issues guidelines for LTPs which influences what transport authorities propose. While major bypasses would feature specifically in a LTP it would be rare to find individual cycle facility proposals in one. Rather the aspirations for the nature of cycle provision would normally feature.
Mandatory cycle lane
A cycle lane which, unlike an advisory cycle lane is for the exclusive use of cyclists. Motorists should not drive or park in it, though loading is sometimes allowed. However, it is almost impossible presently to get the police to enforce such lanes, and they are often ignored. While motorists should not use them, cyclists are not obliged to stay in them. A mandatory lane is signed subtly differently from an advisory lane, the sign showing a white bicycle on a blue rectangle with a white line to the right edge. There is also always a sign in advance of the start of the lane.
Mode; Modal split; Modal share
The different ways people use to get around are called ‘;modes’ by traffic planners. So for example, walking is one mode, cycling another. Bus, taxi and car are others. Walking and cycling are sometimes collectively called ‘soft modes’ or even (pejoratively and inaccurately) ‘slow modes’, or in the context of safety as ‘vulnerable road users’.
Modal split is therefore the proportions in which the different modes are used, and modal share the proportion used by some particular mode. One might say ‘cycling has a 20% modal share’ by which one means that 20% of journeys (on a particular road, or in a particular area, or time of day) are by bicycle.
NCN; National Cycle Network, Route 51, Route 11
The more than 10,000 miles of designated cycle routes in the UK, much of it off-road, established by Sustrans. In our area NCN route 51 runs east-west, especially the section from the City, along Midsummer Common, Ditton Meadows, and Newmarket Road to Bottisham and beyond. NCN route 11 runs north-south, from Shelford and beyond through the City eventually to Ely, though at the time of writing, much of the route has not been completed in its final form.
While for mountain bikers, off-road tends to mean on rough terrain, for us urban cyclists, we usually mean on a path usually alongside a road, but also across commons, alongside rivers: essentially anywhere not shared with motor-traffic.
Pedestrian phase (of traffic lights); All-red phase
The point in a phasing of traffic signals (traffic lights) at which all vehicles from all directions, including cycles, are stopped at a red signal to allow time for pedestrians to cross. In the Netherlands, cycles are often also allowed to use this phase in any direction.
A traffic signal (traffic light) controlled crossing of a road for pedestrians only. Cycles are not permitted to cycle across one. They can be distinguished from ‘toucan’ crossings which cyclists are allowed to use, by the absence of green cycle symbols on the lights.
Permeability; Permeable by pedestrians/cyclists
The extent to which an area is accessible to cyclists, and in particular the extent to which adjacent areas are accessible to each other. Crime reduction people often favour reducing permeability (thieves can’t so easily run away and alleyways aren’t then a haunt for troublemakers). However they tend to be car drivers who ignore the massive inconvenience caused by much longer journeys for those on foot or bike.
Phasing/phases (of traffic lights)
The sequence in which traffic signals (traffic lights) change to allow traffic to move in different directions. This can be quite sophisticated, to include filters. Mostly, a signals engineer will try to phase lights to maximize the amount of traffic a junction can handle. This is often detrimental to cyclists because it complex phasing requires extra traffic lanes (so less room for cyclists), and generally discriminates against cycle specific phases (for example at the Brooklands Avenue end of Hills Road bridge).
Personal injury accident
Technical term used by traffic planners etc for those accidents in which an injury occurs – as opposed to those in which there is only property damage. See also Killed and Seriously injured – rating the severity of injuries.
Pinch point; road narrowing
A point where the road narrows, usually deliberately because of a build-out or central traffic island installed as part of a traffic calming scheme. These are of especial concern to cyclists because vehicles often will not wait for a cyclist in the narrow section. They try to overtake in the gap or will not give way when they should, putting cyclists at serious risk.
Pram arm; Pinch stile
A feature pretty much unique to Cambridge where a gap either between houses or between railings onto open land (e.g. the commons) is narrowed at waist level by a pair of triangular substantial metal loops. These iniquitous devices not only prevent tricycles and bikes with trailers or large baskets from using routes which they are allowed, even encouraged, to use, but also discriminate against people with prams and buggies, and people in wheel chairs.
Cambridge Cycling Campaign has been highly successful in getting most of the pinch stiles accessing the common (where they were installed aeons ago to prevent cattle escaping onto the roads) replaced by cattle grids (and more recently with non-slip bars). However some installed for supposed speed reduction purposes specifically on cycle routes still exist, a notable example being at the ends of the alleyway connecting Colerdige Road and Marmora Road on the South-East Cambridge cycle route.
Bend radius (plural radii); Turning radius
A measure of how tight a bend in the road is, as in the radius of the notional circle of which the bend is a part.
Too tight (too small a radius) and the bend is hard to negotiate. Also long vehicles tend to encroach more to the left on tight radius bends, so a cyclist on their nearside is highly vulnerable.
Where adjacent traffic lanes are controlled separately by their own traffic signals – sometimes called filters or slip lights – the lane that has the green light – the green phase – is called the running lane.
Section 106 (s106) agreement
A planning device named after the section of the parliamentary Act which allowed it whereby planners can negotiate with developers for money to be paid by the developers for public works which will mitigate the effect of a development. A section 106 agreement may then lead to planning permission being granted when it would not have been otherwise. This could be traffic related – improving a junction, or even a bus service, where extra traffic caused by a development would be a problem – or might be to do with increased population – building a school for example.
While the County Council is generally good at consulting the public about changes to the road network, changes arising from section 106 agreements can escape this consultation and come as an unwelcome surprise for cyclists, as they are often to do with increasing road capacity.
Shared-use; Shared use pavement;
Segregated shared-use; Unsegregated shared-use
A footway (pavement) on which cyclists are also permitted to ride. There are two kinds:
- unsegregated, where cyclists and pedestrians both share the whole space of the footway. These are indicated by a sign with a white cycle and pedestrians, one above the other, on a blue circular background, and usually a white cycle painted on the pavement.
- segregated, where cyclists and pedestrians are separated by a white line. These are indicated by a sign with a white cycle and pedestrians side by side separated by a white line (note the subtle difference) and a cycle symbol painted on the side for the sue of cyclists. Occasionally the pedestrian side may have a pedestrian symbol painted on it, though this is unusual in Cambridge. On this type, cyclists are obliged by law to keep to the side allocated to them (though limited widths for passing oncoming cycles often make this impossible in practice), though pedestrians are technically allowed use the whole width if they are determinedly suicidal.
Shared-use is also now often delimited by corduroy slabs laid at the start and end which are designed to help people with sight difficulties distinguish pavements where cycles are likely to be present.
The Sheffield Rack is the ubiquitous design of cycle parking stand – a hoop of metal tubing which a cycle an be securely locked to. Variants have been tried, some of which are more successful than others. Providing they support the bike properly (unlike the ‘nappy pin’ design in the City Centre), can be securely locked to and have sufficient space around them, the specific design is probably not all that important. Sheffield stands are however, relatively cheap and easy to specify.
A direct line of sight, usually in the context of one road user being able to see another. See also visibility splay
Slip lane; Left-turn lane
A traffic lane which allows vehicles to bypass the main traffic lane, usually to turn left, for example approaching a filter light at traffic lights. For example consider the left turn from East Road into Mill Road. Sometimes also at a roundabout to allow left turns without the need to give way to traffic on the roundabout, as for example leaving the A14 at Quy to head towards Cambridge. It is much harder for a cyclist to go straight on where such a left turn lane exists, especially where a single lane becomes the left turn lane rather than the straight on lane.
Snicket; Ginnel; Alley; Alleyway
A narrow path which may or may not be available to cyclists, typically between two housing estates, or sometimes to give access to the rear of terraced houses.
An artifically introduced mound in the road intended to slow traffic, distinguished from an ordinary road hump by only taking up part of the road width. If raised humps are used for traffic calming, this is often the best kind, as cyclists can pass to the side unimpeded, provided parkingis properly controlled. See also speed table.
An artifically introduced flat-topped, usually steep-sided, usually block paved mound in the road, especially at junctions or crossings, intended to slow traffic. Contrast with speed cushions, road humps and other kinds of traffic calming.
Speed responsive sign
A usually all-black sign which illuminates with a speed limit sign and flashing orange lights when a vehicle is detected moving towards it too fast. Also sometimes used approaching a sharp bend or hazardous junction, when the illumnated sign will be the appropriate warning, though these are unusual in Cambridgeshire. A form of traffic calming.
Staged (2-stage/ 3-stage/multi-stage) pedestrian/cycle crossing
When this is a zebra crossing, this can help pedestrians, but when controlled by traffic lights, that is a pelican crossing or toucan crossing, this means that those crossing have to wait twice or three times for the signals to change to red instead of only once at a continuous crossing. In addition, the islands often enclose the pedestrian in metal railings – a cage or pen – with openings at opposite ends, forcing a dog-leg manoeuvre. Often such spaces are cramped, and where cyclists are allowed to use such a crossing, as well as delays caused by multiple traffic signals, this leads to awkward turns, conflict with pedestrians and congestion in the caged area.
Sustrans is an organisation based in Bristol which is responsible for the establishment of the National Cycle Network (NCN), more than 10,000 miles of routes signed for cyclists, much of it off-road. Routes 11 and 51 pass through Cambridge.
Tiles, usually red, with slightly raised dimples, set into the pavement on the road edge to indicate to blind or partially sighted people through their shoes a road crossing point. Though primarily at pelican crossings or toucan crossings, they are also increasingly used simply at uncontrolled points where a sighted pedestrian would naturally cross the road. See also Corduroy slabs.
A traffic signal (traffic light) controlled crossing of a road shared between pedestrians and cyclists. (‘Two-can’;… geddit?) They can be distinguished from ‘pelican’ crossings which cyclists are not allowed to use, by the presence of cycle symbols on the lights. Rarely in Cambridge, these are segregated (separate sides for cyclists and pedestrians) as for example at the crossing of Maids Causeway between Fair Street and Midsummer Common. More often though the same space is shared. The signals may be ordinary traffic signals with pedestrian and cycle symbols on them. More recently crossings though simply have small cycle/pedestrian lights at waist level on the poles along with the control buttons. Sometimes these crossings have loops in the road which detect cyclists, so they do not have to press the button to activate the lights.
Lowering traffic speeds by a variety of physical means such as
- road humps (sleeping policemen), speed tables and speed cushions
- road narrowings and buildouts
- speed responsive signs
Traffic signals; Traffic lights
While ordinary mortals talk about traffic lights, road engineers nearly always talk about signals. Signals often have sophisticated phases with filters, and in Cambridge very often advanced stop lines and sometimes cycle filters.
At a junction the cone formed by the lines between an approaching road user – especially when paused at a give way line – and any obstructions limiting visibility of the main road on either side. The better the visibility splay, the safer the junction, as people can see each other earlier and therefore have more time to react.
Vulnerable road users
Zebra crossing (pedestrian crossing)
Indicated by black and white stripes and orange flashing ‘belisha’ beacons, a point where pedestrians may cross the road. Once on the crossing, vehicles must give way to the pedestrian, though often they do not. For this reason, signal controlled crossings – pelican crossings – were introduced. Cyclists may not cycle across either of these kinds of corssing. A further variant in the animal menagerie – the a href=”#toucan”>toucan crossing – common in Cambridge, does permit cycling.
See also multi-stage crossings.