Schematic view of Dublin's Canal Way Cycle Route
Enabled and enforced by innovative use of ITS, Dublin’s new off-road cycle route is proving a hit with commuters, leisure cyclists and walkers alike as Brendan O’Brien explains
7086 Dublin City Council’s vision is to create a city where people of all ages and abilities have the confidence, incentive and facilities to cycle. On-road cycle lanes had already been incorporated into the Quality Bus Corridors design and there is a mix of on- and off-road cycle routes. However, in 2010 the Council began work on a new way of providing cycle facilities.
The Department of Transport-funded Canal Way Cycle Route will provide an off-road and mainly segregated two-way cycle route along two canals which encircle the centre of Dublin. To the north of the Liffey is the Royal Canal and to the South is the Grand Canal with the Samuel Beckett Bridge providing the link between the two.
The first 3.6km stretch of the cycle route opened in 2012 in the city centre, with phases two and three moving into construction during 2014.
These canal routes are designed to be used by everyone from novice bike riders to cycling commuters and kerbs along the path separate cyclists from vehicles and pedestrians. The first section provides a commuter cycle route from the main radial routes into the Docklands area - home to major financial services and IT companies. It also links six Dublin Bike stations, making use of this route very easy for workers and tourists alike.
Dublin is a radial city with many major traffic routes crossing the Canal Way, so the issue of how best to provide for a cycle track crossing these junctions was a major issue. The primary objective was to ensure cyclists are treated in the same manner as road traffic by providing dedicated cycle phases in the traffic signal sequence – so Toucan crossings could not be used. As the path is not a shared route, cyclists could be considered as any other stream of traffic which enabled the council to adopt its Quality Bus Corridors approach. This required upgrading existing traffic signals with separate bicycle detection at each junction along the now opened section and has been achieved with loop and stop-line video detection in preference to cyclist buttons.
A number of Canal Way junctions had no existing traffic signals so 100mm heads traffic signals were installed at each and a separate bicycle phase was implemented using a new type of signalling to resolve bicycle and pedestrian interaction. At these junctions a new ‘nested Pelican’ sequence was introduced so that during the flashing green man phase, cyclists were provided with a flashing amber signal (see illustration). Legislation was introduced to allow this type of operation along with the legal requirement for cyclist to give way to pedestrians during this part of the sequence.
The flashing amber for cyclists is followed by a separate green cycle signal to ensure that cyclists could safely cross, even if there are heavy pedestrian flows – as is the case at many crossings.
In order to minimise conflict between pedestrians and cyclists, and to eliminate the need for cyclists to ride over tactile paving, the waiting areas for pedestrians and cyclist were segregated. In addition, CCTV is installed at each junction to allow traffic management and an element of security for cyclists and pedestrians as all the Council’s traffic cameras are shared in real time with the Irish Police.
Junctions on the Canal Way are predominantly four arm layouts, with large pedestrian, cycle and vehicle numbers in both directions. A 2012 count showed that during the peak about 800 pedestrians and 550 cyclists per hour use each junction.
At each crossing point, the cycle route was provided with dedicated 100mm signals (see pic), and in many cases, due to space constraints, the primary signal for the adjacent traffic lane was mounted on a cantilever pole. This further highlights the separate nature of the route.
Dublin Council’s Traffic Department had already installed a dedicated fibre optic network around the city with multiple separate rings radiating from the Traffic Control Centre in the city centre. The Canal Route was linked to this network at a number of points to provide dual redundancy. In the first phase 22 junctions or pedestrian controllers were connected to network along with 16 cameras.
Most of the Council’s 240 traffic cameras are analogue with multiple fibre optic networks providing the main communication network for both CCTV and traffic controller communications. At the Traffic Control Centre the CCTV signals are divided; one input going to an analogue matrix and the other converted into an IP stream for the secondary digital IP matrix. Dublin’s system uses a Meyertech Analogue Series 3 matrix and at present all the switching and PTZ functionality is achieved through this primary matrix. However, to ease CCTV distribution, and to provide a stand-by matrix, an Indigo Vision IP matrix is also used. Using uncompressed digital transmission maximises flexibility by ensuring the images are available at the in-station without any compression loss and simplifying network security by not providing IP access points at the field equipment.
This required a technical solution to allow multiple CCTV and traffic control systems to be connected along the route. There was also a need to maintain dual redundancy and allow the system to be expanded as further parts of the Canal Way Path are opened up.
AMG’s 3700 series, which the council has used for a number of years, was the chosen solution. It is configured in an eight-channel drop-and-insert configuration over a single fibre to provide eight insert points and one CCTV input plus a bi-directional data channel configured for RS 232. The RS 232 is connected directly to the traffic controllers on the SCATS adaptive traffic control system and at the traffic computer centre each RS232 channel is connected directly to the SCATS hardware via DIGI C/Con 16 multi-channel serial adaptors. As the system allows a point-to-point channel at each location, the multi-channel receiver provides eight separate bidirectional channels with RS 232 interfaces enabling the traffic controller and CCTV to share the same system for maximum effectiveness.
A 100mbps Ethernet connection is available at each node for future use. The 3700 series utilises coarse wavelength-division multiplexing technology to maximise the video and data transmission capability of installed fibres by multiplexing wavelengths together and therefore reducing infrastructure costs. This system enables up to 72 analogue cameras to be collected onto a single fibre.
In case of a failure of the fibre or node, the dual redundancy system will immediately re-route and maintain operation while the network management system will report the failure and location. The 3700’s network management software is linked to the Council’s fault management system to provide automatic notification and identification of faults.
There is provision at field mounted 3700 units for a standard CCTV connection and a point-to-point data channel which Dublin uses to link the traffic signal controllers to the SCATS traffic control system. So each drop and insert circuit has provision for eight CCTV connections and a similar number of RS 232 point to point connections. With the 3700 providing zero control latency and uncompressed digital transmission, the image received at the traffic control centre can be used for multiple applications including video analysis.
The use of three eight-channel 3700 receivers at the traffic centre (more can be added if needed), provides connectivity for up to 24 cameras and traffic controllers (or 48 controllers depending on board type). This has been achieved while using only three fibre cores of the 3.6km cable along the length of the cycle route – leaving plenty of spare capacity for system extensions.
In designing the signalised Canal Way junctions it was decided that the bicycle phase should not only be demand dependant but also vehicle actuated and as bicycle wheel rims are close to the ground they lend themselves to inductive loops detection. A diagonal quadrupole loop design places the loop at an angle across the width of the cycle lane (see illustration) and in practice it is achieving 100% detection as a bicycle crosses the loop. Furthermore, connecting the loop detection to the traffic controller provides an accurate count of bicycles both in real time and via the SCATS system’s integrated reporting tools.
To detect carbon fibre bicycle wheels, the inductive loops are supplemented with above ground video detection utilising a stereoscopic video camera to eliminate false readings from objects moving close to the ground. While this technology was designed to detect pedestrians, it was found it could detect bicycles in a 3m2 detection zone at the stop line, without pedestrians creating false readings.
Table 1 is a SCATS extract showing peak hour traffic flows have not been reduced by adding the cyclist phase in the signals sequence. SCATS system calculations show that the lane capacity (which varies from 1,420 to 1,620 vehicles per lane per hour) has not been reduced by the introduction of the cycling facility. The SCATS count data for actual flows is shown in Table 1.
Sections of the route became available to cyclists from the autumn of 2011 and the first phase of the Canal Way was fully opened in March 2012. Since then the average number of cyclists has grown to more than 3,000 per day with 2013 showing a 22% year-on-year increase.
A survey of weekday cyclists showed 85% of respondents use the route for business related activities while a Sunday survey showed 57% of cyclists use the route once a week or less and 35% of pedestrians use the route for fun. It has also been observed that the route is well used by Dublin Bike users showing the added value of linking to bike stations along this route.
A further survey was carried out six months after opening to determine road users’ perceptions of the new junction layouts and signal sequence using cameras to record road user behaviour and questionnaires for pedestrians and cyclists. Preliminary results suggest that more than 90% of cyclists rate the operation of the junctions as ‘satisfactory’ and a similar proportion of pedestrians preferred the new junction layout. The main reason given by 70% of those who preferred the new junction layout was that it is safer. Approximately 15% of pedestrians said they now walk more, with a majority saying it was because the route felt safer. However, 10% of pedestrians felt the junction layout and signals were hard to understand.
The use of multiple drop-and-insert fibre optic rings has provided substantial benefits with adjacent junctions being converted from leased line to fibre and additional CCTV coverage enhances both safety and traffic monitoring. Dublin City Council will provide the same elements in a uniform design for the next section of the Canal Way which is now moving to the construction phase.
Brendan O’Brien MSc BSc Dip I.T. is head of Technical Services (Traffic) at Dublin City Council with responsibility for all aspects of traffic management. He has experience in both the public and private sector in the fields of traffic engineering and telecommunications.
The Department of Transport-funded Canal Way Cycle Route will provide an off-road and mainly segregated two-way cycle route along two canals which encircle the centre of Dublin. To the north of the Liffey is the Royal Canal and to the South is the Grand Canal with the Samuel Beckett Bridge providing the link between the two.
The first 3.6km stretch of the cycle route opened in 2012 in the city centre, with phases two and three moving into construction during 2014.
These canal routes are designed to be used by everyone from novice bike riders to cycling commuters and kerbs along the path separate cyclists from vehicles and pedestrians. The first section provides a commuter cycle route from the main radial routes into the Docklands area - home to major financial services and IT companies. It also links six Dublin Bike stations, making use of this route very easy for workers and tourists alike.
Dublin is a radial city with many major traffic routes crossing the Canal Way, so the issue of how best to provide for a cycle track crossing these junctions was a major issue. The primary objective was to ensure cyclists are treated in the same manner as road traffic by providing dedicated cycle phases in the traffic signal sequence – so Toucan crossings could not be used. As the path is not a shared route, cyclists could be considered as any other stream of traffic which enabled the council to adopt its Quality Bus Corridors approach. This required upgrading existing traffic signals with separate bicycle detection at each junction along the now opened section and has been achieved with loop and stop-line video detection in preference to cyclist buttons.
A number of Canal Way junctions had no existing traffic signals so 100mm heads traffic signals were installed at each and a separate bicycle phase was implemented using a new type of signalling to resolve bicycle and pedestrian interaction. At these junctions a new ‘nested Pelican’ sequence was introduced so that during the flashing green man phase, cyclists were provided with a flashing amber signal (see illustration). Legislation was introduced to allow this type of operation along with the legal requirement for cyclist to give way to pedestrians during this part of the sequence.
The flashing amber for cyclists is followed by a separate green cycle signal to ensure that cyclists could safely cross, even if there are heavy pedestrian flows – as is the case at many crossings.
In order to minimise conflict between pedestrians and cyclists, and to eliminate the need for cyclists to ride over tactile paving, the waiting areas for pedestrians and cyclist were segregated. In addition, CCTV is installed at each junction to allow traffic management and an element of security for cyclists and pedestrians as all the Council’s traffic cameras are shared in real time with the Irish Police.
Junctions on the Canal Way are predominantly four arm layouts, with large pedestrian, cycle and vehicle numbers in both directions. A 2012 count showed that during the peak about 800 pedestrians and 550 cyclists per hour use each junction.
At each crossing point, the cycle route was provided with dedicated 100mm signals (see pic), and in many cases, due to space constraints, the primary signal for the adjacent traffic lane was mounted on a cantilever pole. This further highlights the separate nature of the route.
SCATS Traffic Controllers
Dublin uses the Australian SCATS (originally the Sydney Coordinated Adaptive Traffic System) and as part of the Canal Way project all the controllers along the route were connected to the SCATS fibre optic communications network. Therefore, one of the first decisions was to install longitudinal ducting along the route sections in the city area to house the fibre optic cable connecting the ITS infrastructure and to allow for extension over the remaining Canal Way phases.Dublin Council’s Traffic Department had already installed a dedicated fibre optic network around the city with multiple separate rings radiating from the Traffic Control Centre in the city centre. The Canal Route was linked to this network at a number of points to provide dual redundancy. In the first phase 22 junctions or pedestrian controllers were connected to network along with 16 cameras.
Most of the Council’s 240 traffic cameras are analogue with multiple fibre optic networks providing the main communication network for both CCTV and traffic controller communications. At the Traffic Control Centre the CCTV signals are divided; one input going to an analogue matrix and the other converted into an IP stream for the secondary digital IP matrix. Dublin’s system uses a Meyertech Analogue Series 3 matrix and at present all the switching and PTZ functionality is achieved through this primary matrix. However, to ease CCTV distribution, and to provide a stand-by matrix, an Indigo Vision IP matrix is also used. Using uncompressed digital transmission maximises flexibility by ensuring the images are available at the in-station without any compression loss and simplifying network security by not providing IP access points at the field equipment.
This required a technical solution to allow multiple CCTV and traffic control systems to be connected along the route. There was also a need to maintain dual redundancy and allow the system to be expanded as further parts of the Canal Way Path are opened up.
AMG’s 3700 series, which the council has used for a number of years, was the chosen solution. It is configured in an eight-channel drop-and-insert configuration over a single fibre to provide eight insert points and one CCTV input plus a bi-directional data channel configured for RS 232. The RS 232 is connected directly to the traffic controllers on the SCATS adaptive traffic control system and at the traffic computer centre each RS232 channel is connected directly to the SCATS hardware via DIGI C/Con 16 multi-channel serial adaptors. As the system allows a point-to-point channel at each location, the multi-channel receiver provides eight separate bidirectional channels with RS 232 interfaces enabling the traffic controller and CCTV to share the same system for maximum effectiveness.
A 100mbps Ethernet connection is available at each node for future use. The 3700 series utilises coarse wavelength-division multiplexing technology to maximise the video and data transmission capability of installed fibres by multiplexing wavelengths together and therefore reducing infrastructure costs. This system enables up to 72 analogue cameras to be collected onto a single fibre.
In case of a failure of the fibre or node, the dual redundancy system will immediately re-route and maintain operation while the network management system will report the failure and location. The 3700’s network management software is linked to the Council’s fault management system to provide automatic notification and identification of faults.
There is provision at field mounted 3700 units for a standard CCTV connection and a point-to-point data channel which Dublin uses to link the traffic signal controllers to the SCATS traffic control system. So each drop and insert circuit has provision for eight CCTV connections and a similar number of RS 232 point to point connections. With the 3700 providing zero control latency and uncompressed digital transmission, the image received at the traffic control centre can be used for multiple applications including video analysis.
The use of three eight-channel 3700 receivers at the traffic centre (more can be added if needed), provides connectivity for up to 24 cameras and traffic controllers (or 48 controllers depending on board type). This has been achieved while using only three fibre cores of the 3.6km cable along the length of the cycle route – leaving plenty of spare capacity for system extensions.
Traffic Signals and Bicycle Counts
Phase sequences at the SCATS-controlled junctions are demand dependent so accurate vehicles detection is essential and requires dependable detection of bicycles as a separate traffic stream. The correct detection information triggers the required phase and enables the SCATS system to maximise the junctions’ performance.In designing the signalised Canal Way junctions it was decided that the bicycle phase should not only be demand dependant but also vehicle actuated and as bicycle wheel rims are close to the ground they lend themselves to inductive loops detection. A diagonal quadrupole loop design places the loop at an angle across the width of the cycle lane (see illustration) and in practice it is achieving 100% detection as a bicycle crosses the loop. Furthermore, connecting the loop detection to the traffic controller provides an accurate count of bicycles both in real time and via the SCATS system’s integrated reporting tools.
To detect carbon fibre bicycle wheels, the inductive loops are supplemented with above ground video detection utilising a stereoscopic video camera to eliminate false readings from objects moving close to the ground. While this technology was designed to detect pedestrians, it was found it could detect bicycles in a 3m2 detection zone at the stop line, without pedestrians creating false readings.
Table 1 is a SCATS extract showing peak hour traffic flows have not been reduced by adding the cyclist phase in the signals sequence. SCATS system calculations show that the lane capacity (which varies from 1,420 to 1,620 vehicles per lane per hour) has not been reduced by the introduction of the cycling facility. The SCATS count data for actual flows is shown in Table 1.
| AM | PM | Daily | |||
|---|---|---|---|---|---|
| Date | Peak | Total | Peak 08:00 - 09:00 | Total | Total |
| 27.10.2011 | 545 | 3099 | 437 | 3691 | 6790 |
| 12.04.2012 | 520 | 2695 | 411 | 3720 | 6415 |
| 25.10.2012 | 562 | 2854 | 469 | 4214 | 7068 |
| 12.04.2013 | 571 | 2854 | 437 | 4090 | 6944 |
Monitoring
As the nested pelican signal sequence is new to Ireland an addition road safety audit was carried out to assess the safety of the signal sequence prior to first operation. This found nothing inherently dangerous with the proposed signal sequence.Sections of the route became available to cyclists from the autumn of 2011 and the first phase of the Canal Way was fully opened in March 2012. Since then the average number of cyclists has grown to more than 3,000 per day with 2013 showing a 22% year-on-year increase.
A survey of weekday cyclists showed 85% of respondents use the route for business related activities while a Sunday survey showed 57% of cyclists use the route once a week or less and 35% of pedestrians use the route for fun. It has also been observed that the route is well used by Dublin Bike users showing the added value of linking to bike stations along this route.
A further survey was carried out six months after opening to determine road users’ perceptions of the new junction layouts and signal sequence using cameras to record road user behaviour and questionnaires for pedestrians and cyclists. Preliminary results suggest that more than 90% of cyclists rate the operation of the junctions as ‘satisfactory’ and a similar proportion of pedestrians preferred the new junction layout. The main reason given by 70% of those who preferred the new junction layout was that it is safer. Approximately 15% of pedestrians said they now walk more, with a majority saying it was because the route felt safer. However, 10% of pedestrians felt the junction layout and signals were hard to understand.
Conclusions
Dublin’s Canal Way Cycle Route has proved very popular with cyclists and demonstrated that a high quality route will attract additional cyclists (the number of cyclists on adjacent roads has remained similar). The adaption of ITS equipment not normally used with cyclists - such as CCTV, video and bicycle loop detection - has enabled the cycle path to be treated as a traffic route.The use of multiple drop-and-insert fibre optic rings has provided substantial benefits with adjacent junctions being converted from leased line to fibre and additional CCTV coverage enhances both safety and traffic monitoring. Dublin City Council will provide the same elements in a uniform design for the next section of the Canal Way which is now moving to the construction phase.
Brendan O’Brien MSc BSc Dip I.T. is head of Technical Services (Traffic) at Dublin City Council with responsibility for all aspects of traffic management. He has experience in both the public and private sector in the fields of traffic engineering and telecommunications.
