How to Measure Public Transport Quality: Essential Steps

Introduction

Planning an efficient public transportation system begins with network design. Defining the routes of the lines and connecting them into an integrated network; scheduling a timetable and making the necessary transfers as convenient as possible; balancing service quality, ridership, operating costs and fare revenues.

Without a reasonable network design, sustainable operations will fail. Every decision you make in this first step will cost or save you money in operations and is the key to efficient public transportation. 

But designing an “ideal network” is difficult. There are many requirements to meet, and some of them conflict with each other. Who should the perfect network be for? The passengers, the operator, or society? Most likely, there will not be a perfect network, but rather an optimal network that balances the different interests. The main question then remains: what is a good network design? How can we define its quality?

Understanding the demand of your network

Network design begins with understanding the users. The planned network should be designed around the desired movement of people. This means knowing how many people want to travel from which orinign to which destination, when they want to travel, and for what purpose.

How do you get hold of this data? One option is to use data from the existing PT service. Analyzing automatic count data from vehicles and stops, or e-ticketing data, shows the usage of your service. But this counting and measuring only reveals the current status. It doesn’t tell you about potential demand for unserved routes or future developments.

Demand modeling solves this challenge. It creates synthetic demand based on socio-economic and behavioral data. You can then select the modal split you want to achieve with your PT service. The potential demand for public transport is shown in the resulting Origin-Destination (OD) matrix.

Planning for the optimum result

“A developed country is not a place where the poor have cars. It’s where the rich use public transportation.”
Gustavo Petro

Planning the optimal network means knowing the requirements of each stakeholder. Finding the best balance between these perspectives defines the quality of the network you design.

The passengers

Here, the goal is to provide a quality service to people who want to use public transportation and prefer it to private vehicles.

The main requirements of PT passengers are:

Accessibility: How far will passengers have to walk to the next or best stop? Does the infrastructure provide easy access to public transportation?       

Connectivity: Does the network meet the demand for public transport, i.e. does the network connect passengers’ origins and destinations? How often do passengers need to transfer to reach their destination?

Frequency: How often is the service available? Is there a way to reduce transfer wait times?

Travel time: How long does it take to get to the destination, especially compared to other modes of transportation?

Reliability: Is the schedule designed to withstand the daily challenges of operation? Is it possible for passengers to reliably plan their trip and arrival time? How can the network-wide impact of single service delays be minimized? Can we guarantee important connections for transfers?

Comfort: Provide a safe and comfortable environment on vehicles and at stops. Prevent overcrowding on vehicles and at stops. Make it easy for everyone to get on and off the vehicle. 

The operators

The ideal service for passengers, however, is not the same as the operator’s requirements. These are the parameters that the operator is looking for:

Cost: How to operate a service according to the PT Master Plan at minimum cost. Considering the cost of vehicles, maintenance, operating kilometers and hours. Especially how to minimize the working hours of the drivers.

Revenue / Budget: How to get a margin from ordered services and operation? Or in case of contract and subsidy: Which PT service is possible with the given budget.

Society

Society, mostly represented by public authorities, also has a strong interest in efficient public transport. Their main objective is to increase ridership. The use of the PT service is important because it contributes to:

Social participation: Public transport provides mobility for people who can’t use other modes of transport such as bicycles or cars.

Congestion prevention: Public transportation helps relieve traffic congestion. Pooling passengers in large vehicles is essential for travel in densely populated areas.

Road safety: Riding public transportation is much safer than driving a car. This is true for drivers and passengers, but especially for non-motorized users such as pedestrians and cyclists due to the reduction in traffic.

Reducing emissions: Public transport helps to reduce noise and air pollution. It’s beneficial to the goal of decarbonizing transport.

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To achieve the optimal network, good public transport design must balance all the above requirements. A perfect network for the passenger won’t last long if the operator’s budget is small. A minimum service that fulfills an unambitious master plan is cheap, but misses the potential for a more livable city.

How to optimize transit networks

While all cities and road networks are different, there are some design principles that help create a good network design:

Simple networks: Helps the passenger understand the service. Results in a manageable number of dependencies in the operation.

Hierarchy: When there is a clear hierarchy of transportation systems, the user can identify the trunk and feeder lines. It helps the operator make decisions about routes that are ridership-oriented or coverage-oriented. Planning the appropriate vehicle types and schedules is much more intuitive.

Coverage: Services should be close to where people want to go or start. But this must be balanced with the simplicity and directness of the service.

Straight and short routes: Avoiding detours optimizes travel time and minimizes operating costs. Shorter routes mean fewer delays, but more transfers.

Demand-driven service frequency: Use high frequencies where demand is needed and avoid overcrowding. Coordinate transfer schedules where frequencies may be low to save operating costs. Consider the time series of demand to adjust frequencies.

Network connectivity: Planning networks, not lines, means knowing the relationship of traffic and ensuring easy transfers within the planned network and to other surrounding networks.

How to assess a network design

Given these principles, your network design will be good, but how do you measure it? What indicators will support your idea of a good network design? What indicators can help you compare different scenarios? Here are the most common ones:

Accessibility: How many people or locations are within a certain radius of your stops?

Connectivity: Often shown in isochrones. How many people or places can be reached in a given time. What’s the mean number of transfers?

Availability: Number of lines, arrivals and departures per stop.

Ridership: Ridership is the final indicator of good network design from the passenger’s perspective, because people will use an attractive transit service. In the planning stages, assignment methods bring demand and supply together to calculate ridership on the network.

Efficiency: The ratio of  performance to production. Production is the effort to provide the service. This leads to its capacity. So the number of trips, their length and the size of the vehicles. The performance is the utilization of the service, the ridership in vehicles. It is mostly measured in terms of the number of passengers and the distance they travel. The ratio gives you an indicator of overcrowding or inefficient service if vehicles are empty.

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You will often see accessibility assessments used to prove the quality of a network design. Accessibility is important because without it, people would be excluded from the service. But it’s only one building block. If you’re just aiming for accessibility, you’re aiming for the captive rider, people who have no choice but to take public transportation. Aiming for ridership means you want to make your public transportation service as attractive as possible. So the ultimate indicator is efficiency. Comparing the passenger’s and the operator’s point of view leads to a sustainable public transport.

Software for public transport design

To achieve this goal, planners have been working with pen and paper for decades. Later, they developed massive masterpieces of Excel files and struggled to maintain them. But today, standard software supports the planning process and even engages your partners in a collaborative environment.

Here are some of the benefits of using software to design public transportation:

• It visualizes your data
• Implements workflows without time-consuming and error-prone data transfer. 
• Provides maps and editors designed for design purposes
• Uses georeferencing and intersection of data
• Provides immediate feedback on changes to evaluate and compare scenarios
• Accessible to the entire team and stakeholders.

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New developments provide methods to generate an automated network design from a given network infrastructure and demand. Utility functions manage the balance between the competing demands of passengers, operators, and society. Multiple results show not just the best, but multiple good solutions. These scenarios can then be evaluated and compared within the same software.

This doesn’t replace the creativity and knowledge of the planner, but it does provide support and help to generate new ideas.

For more information, check out the “Automated Public Transportation Design” Deep Dive Session.