Edit Network help

Principles behind drawing maps for Journey Planning

The notes below refer to a previous era (before end March 2009) when the maps were generated by tracing satellite imagery. Since then all routing information is derived from the www.openstreetmap.org project and you can use the CycleStreets version of the editor to alter the map data. Changes to the maps in that system filter through to cyclestreets after a few days. The notes below are maintained as they do give some insight into how the routing system works.

This page introduces the important points that should be understood in order to contribute effectively to the journey planning map. This information should help you to use the tools for changing the map under the "Edit network" tab on this section of the website.

Drawing paths and nodes

Effective journey planning begins with an accurate map of the highway network.

Maps usually record the centre-lines of roads and where they join. For instance, a junction between a busy main road and a side road might be drawn as shown on this photograph:

See caption.

The junction of the centre-lines of Lensfield Road (main road, blue), and Tennis Court Road (quiet street, black).

The centre-lines of roads are drawn as a connected series of points that form a path. Where two paths join at the same point this is known as a node. Journey planner can only find a route from one path to another if they are joined at a node.

See caption.

Showing a node (green dot) at the junction of the three paths.

So, the first principle in drawing maps for the journey planner is:

When there is a route from one path to another, it is essential that the two paths are joined at a node.

Note: Nodes are not automatically displayed on the maps under the Edit network tab, but they can be displayed temporarily by using the "Node check" button, when it is available.

Classification of highways

Roads are often classified according to the amount of traffic they carry, and are drawn on maps in a variety of colours and styles.

In journey planner the classification used is called types of provision. Each type of provision describes a road surface or highway feature, such as, for instance "Busy road", "Quiet Street", "Cycle lane" or "Pavement". Each provision type has its own colour and style which is used to draw the associated paths on a map.

The provision types also define information that is useful for journey planning. For instance a path that has the provision type "Pavement" is walkable but not cyclable. Provision types also define the maximum speed at which cyclists using such links can ride and the relative quietness of that type of link.

The provision table is not shown as this code is in transition [May 2011].

Where there are alternative paths between nodes, journey planner uses this classification to choose routes most suited to a user's preferences.

This brings us to the next most important principle:

When drawing paths on the map, it is important to choose the best matching provision type.

These two basic principles provide enough knowledge to draw basic routing maps of the cycle network.

Detailed Junctions

Using the centre-lines of roads for journey planning has limitations, as is evident in the first photograph above. The cyclist is in a right turn traffic lane which is not represented in the map of the two connecting lines. The cyclist is going to turn into a one-way street with a contra-flow cycle lane. Better journey planning can be accomplished by capturing all those details.

Showing main traffic paths at this junction.

Showing main traffic paths at this junction.

This photo shows all the main traffic paths at this junction along each lane of the carriageway. When drawn like this the roads do not join at a single node. Each maneouvre through the junction needs to be drawn.

See caption.

Detail showing all the paths and maneouvres through the junction. The pink lines are maneouvres of type "Cross busy road".

In this picture all the paths and maneouvres that cyclists can perform are represented. All of the paths shown are one way, but the arrows are ommitted to avoid cluttering the image. Where paths join, a node is shown as a filled colour circle. The colour of the circle indicates the number of paths that join at that node. Yellow means 2, and green means 3. (This colour scheme comes from the game of snooker in which balls have points from one to seven according to their colour: red, yellow, green, brown, blue, pink, black.)

The busy paths are shown using a blue line, and they correspond to the provision type "Busy Road". The red line is the provision type "Cycle Lane", and the black is "Quiet Street". The maneouvres are also paths, but are shorter and more curved and they correspond to the turns. The turns into and out of Tennis Court Road are drawn in a pink colour, that corresponds to the provision type "Cross busy road".

To see how this junction appears as drawn on the map, view the junction of Lensfield Road with Tennis Court Road on the Edit network page.

Although it might look relatively complicated at first sight, this network captures a lot of information about the junction. For instance, the "Cross busy road" provision type acknowledges this is an advanced maneouvre, and that there is quite often a delay before the rider is able to make it. That information is used by journey planner when searching for either quietest or fastest routes through this junction. It might conclude that an alternative route, that turns right further down the road is faster, or that a route that uses a nearby crossing is quieter.

Drawing all the paths through a junction and ensuring that they are all properly joined is a time-consuming activity. However because the journey planner can handle both basic and detailed junction descriptions it can be treated as an incremental task. Start by drawing basic routing maps of your area. This enables the journey planner to do basic route planning. Sometime later the map can be edited with full path details for as few or as many junctions as you please.

Ways

In the first photograph it was easy to name the paths. The blue path was Lensfield Road, and the black path was Tennis Court Road. Now that all the paths through the junction are drawn there needs to be a consistent way of labelling all the paths.

Paths are grouped together into an object called a way. All the paths on a road usually belong to the same way. So here, there will be one way called Lensfield Road, and one called Tennis Court Road.

In the last picture of the junction there are three blue lines that represent the paths along Lensfield Road. They each belong to the Lensfield Road way. Similarly the black and red paths belong to the Tennis Court Road way.

That leaves the maneouvres. These short paths have ends in both ways. So the convention adopted is that a maneouvre belongs to the same way that it starts from. For instance the path that shows the left turn into Tennis Court road from Lensfield Road belongs to the Lensfield Road way, but the right turn out of the cycle lane belongs to the Tennis Court Road way.

When paths are added to the map using the tools under the Edit Network tab, there is an opportunity to assign the way they belong to, or to create a new named way.

Terminology

Point
A co-ordinate of longitude, latitude. Points belong to Paths.
Path
A route along a highway. Paths have a provision type, and belong to a way.
Node
A point where two paths join.
Maneouvre
A short path that represents a turn, often but not always from one Way to another.
Way
A named group of paths, usually representing a road or street.
Provision type
Attached to paths, provision types define how to draw the path on a map. Journey planner uses the attributes in a path's provision type to choose which routes to follow for journey planning.

The Edit network tab

The network that the Journey Planner bases for its route suggestions can be viewed under the Edit network tab. Users who have signed in to the site can use the tools under that tab to add to or edit the network.

A map is displayed with the existing known routes overlayed. The panel on the right of the map changes in response to what is selected or clicked on the map. Follow the displayed suggestions to make changes on the map. You can usually undo changes by clicking the Unselect or Cancel button that appears near the top of the right hand panel in some situations.

Notes for Advanced Users

Some complex junctions

View the current state of:

Traffic Lights and Advanced Stop Lines

Continuing in this theme of precision it is possible to include sections of advanced stop line. See Mill Road, Gwydir Street, St. Barnabas Road junction. There is a category for Traffic Lights. This should be used for the section of road immediately beyond the stop line. The reason for that is that traffic light sections have a pause, representing the delay inherent in using them. The delay does not affect your arrival at the stop line, but does come in if you want to go beyond that.

Tips

Frequently Asked Questions

Why do paths I want to connect to disappear?
Paths are only drawn if a point on the path lies within the map boundary. This can mean that sometimes when you pan the map viewport around a path might disappear. This can be disconcerting, and is probably a bug that needs fixing. Without a fix for this all I can suggest is that you edit the offending paths to have more frequently spaced points.

Naming Ways and Paths

Ways usually represent roads or streets. They should be given the obvious name, such as "High Street", or "Acacia Avenue". There is no need to include the district, town or village to which they belong. The names you add here will be reproduced in the journey listing. If you don't know the name of the road enter something like "Unknown country road" or "Unknown Street".

Paths can also be assigned with a note that helps clarify where they go or any other useful information, for instance "This access gate takes solo bicycles only".

The route listing will also display any maneouvre associated with the path.

We welcome your feedback, especially to report bugs or give us route feedback.
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