There are plenty of ways to enhance the bus network so that buses flow better. This can have the benefit of improving the reliability of bus services, the street environment, road safety for all road users and reducing congestion.
With better public transport networks, residents and businesses can benefit from better economic opportunities including more jobs and higher footfall.
Buses operate more reliably, allowing for a decrease in the number of buses required to deliver a bus service. This helps to reduce costs that can be passed on to bus passengers using the network.
Buses can be prioritised through a number of options and these options can be broken into two categories.
1. Link Improvements where the bus gets priority over a set distance
2. Intersection Improvements where the bus gets priority at a junction
There are different types of link improvements and they can have different types of restrictions on vehicle type. This can be specified in the TRO and clearly marked on the signs.
- Bus only
- Bus and cycle only
- Bus, cycle and taxi only
- 2+ car lane
- No car lane
Other vehicles can be considered as well and these are reviewed as part of the Traffic Regulation Order that is sought for the bus lane.
These can create space for buses to flow smoothly past areas of general road traffic congestion. Buses can depart from bus stops smoothly because the risk of overtaking vehicles is reduced. Dependent on the layout chosen, buses can join general traffic where they are required to cross, merge with it.
They can be used by multiple operators buses without having to adapt the bus.
Bus lanes can be integrated into other bus priority measures including bus priority through a junction and specific measures that allow buses to only perform certain turns and manoeuvres at a junction.
Segregated Bus Roads
In a number of cases, these are mistaken for bus lanes. A specific road is created for buses. Sometimes there will be provision for cyclists and enforcement is through active measures such as cameras and enforcement officers.
They can be implemented quickly without the difficulties that guided busways can have.
The structure of guided busways is variable dependent on the construction method used. In most cases, a concrete track is created with raised kerbs that allows adapted buses to travel on it. Other vehicles have difficulties using the track due to the width and space between the two tracks.
Buses can achieve higher speeds on these tracks because the route is clearer and there are fewer risks when passing other vehicles and objects. They are also more defined as infrastructure because of the track so possible users are more likely to be attracted to them. Users are more likely to travel further to bus stops (because the stops are also invested in with shelters, real time information and pedestrian crossings of nearby roads), so the number of bus stops can also be reduced.
The bus does have to slow down where they are joining and leaving the track. They have to be careful where there are gaps for pedestrian crossings.
Improvements can be made to junctions (intersections) to improve how buses run through them. They are usually integrated with a section of link improvements to create a bus gate into the junction. They can also be found at the end of a link improvement to maximise the benefit of it.
The bus lane at Kirkstall ends with a set of traffic lights that sits at the end of the general traffic lane. The lights are activated by an approaching bus in the bus lane. The bus then merges into general traffic without having to wait until a vehicle lets it merge.
There can be a separate access to a junction for buses. In addition, buses can be given an exemption to banned turns.
Some systems can be active and some systems can be passive. Active systems require sensors to operate. Basic systems use a passive sensor on the junction whilst advanced systems use systems located on the vehicle.
Pre signals and Bus advance areas
Vehicles can be detected by GPS technology or beacons placed at the roadside.
Green extension – an approaching vehicle is detected and the green phase that support the movement of that vehicle through the junction is extended by a maximum period of time.
Early Green – an approaching vehicle is detected and the green phase for other movements are shortened.
Early red – an approaching vehicle is detected so a red phase triggers early and the junction move through the other green phases quickly so that the vehicle can travel through on a green light.
Phase rotation – the order of phases at a junction are swapped to ensure that the vehicle arrives at a green phase
Phase insertion/recall – an extra green phase is put in place when a vehicle approaches. The likelihood of this occurring can be varied.
Actuated phase insertion – the green phase for an approaching vehicle is not activated until it arrives. This is particularly popular in schemes involving light rail systems.
These schemes effectiveness are dependent on the size of the green phase. If they implemented poorly, the scheme could cause more traffic problems because of the disruption to the other flows through the junction.