On Track with Automated People Movers

Automated People Movers or APMs have long been a valuable, and largely reliable, transit option for airports and transportation hubs.

The demand for these transit systems to help transport passengers with ease and comfort continues to grow—as do the challenges. A recent Global Automated People Mover System Market Research Report 2024 noted that the global APM market valued at US$1.1 billion in 2023, is expected to reach US$1.6 billion by 2030, with the largest application in airports and urban transit.

The successful implementation of these systems comes down to clarity of purpose and a keen awareness of industry challenges. Familiar concerns in today’s environment range from construction delays to rising costs of materials and labor. For APMs, there’s the added complexity of integrating with existing infrastructure while minimizing impacts to existing operations.

As airport owners look to APMs to better streamline passenger transit activities, lessons learned from those currently under construction provides valuable insight.

Options and Opportunities

 An APM system runs on a fixed guideway, and generally, they do not directly interface with any other transportation activities or crossings. They will usually go over or under roadways where possible to avoid having a shared crossing.

There are two main types of APM systems: cable pull and rubber tire. Cable pull systems are about half the cost of rubber tire, but that’s a small piece of the decision making when it comes to airport transit solutions.

Selecting the right one for any airport owner typically comes down to passengers per hour or capacity and flexibility. Rubber tire systems typically handle about 100 people with baggage per car whereas cable-pull is less than 50. As well, cable-pull systems have less flexibility when switching tracks.That said, the Mexico City Benito Juarez International Airport and the Toronto Pearson International Airport both have quality cable-pull systems that work for the capacity requirements in those environments. However, a cable-pull APM solution likely will not work well for many airports, particularly international, simply because of the need for capacity.

One trend that has been noted in past APM projects is related to quantity of bids. In many cases, if an organization opts to allow a cable-pull solution in the bidding process, it could result in rubber-tire vendors pulling out, usually because of the pricing difference.

As an example, the Port Authority of New York and New Jersey (PANYNJ) has moved to build a 2.5-mile APM system to replace the existing AirTrain system at Newark Liberty International Airport (EWR). The AirTrain Newark Replacement Program will replace the current system. The request for proposal (RFP) did not explicitly disallow cable-pull systems, as a result one of the main rubber tire suppliers dropped out.

Rethinking Capacity

A number of airport entities, such as Denver International Airport, are planning for new APMs to ease vehicle-based passenger movement between airport commercial services locations—and procurement decisions go well beyond APM type.

A tailored approach to the RFQ and RFP process is essential to meeting project goals and reducing potential contract scope gaps. A detailed plan covers system design, construction and full system verification to central control, SCADA requirements and train operations. It answers questions about desired system headway, anticipated Passengers Per Hour Per Direction, expected availability, weather/environmental considerations, and ADA concerns.

The ability to increase capacity is always a critical consideration for any APM, particularly in a location like Denver.

The Denver International Airport, which is one of the newer airports in the country (built in 1995), is now 50% beyond its original design capacity and continuing to grow. It could easily go to 100 million passengers in the coming years.

Keep in mind, the current APM (aka AGTS) system that moves between concourses doubled its train length from 2 car trains to 4 car trains just as the airport first opened. It’s important that the vision for growth is accurate—and then allow for expansion.

As the Wind Blows

Beyond the importance of meeting capacity to support current and future growth, weather and security of APM systems are often top-of-mind. Above ground APMs, whether cable drawn or rubber tire, are subject to weather restrictions. Generally with winds in excess of 60 mph, above ground systems will halt service, or certainly limit their speed. Above 80 mph will stop all service. While heavy rain or snow is usually not an issue, a freezing rain/drizzle can cause the power rails and running surfaces to freeze unless they have pre-installed heating systems.

Denver International, for example, is looking to develop an outside system that moves from the airport to rental car facilities—weather is obviously a major factor when evaluating reliability. In the last 10 years, hailstorms have caused more than $5 billion in insured damage in Colorado—much of it to vehicles, which includes transport systems.

While hail causes significant financial impact, the other Denver weather factors need to be considered. Snow, freezing rain, high winds, tornados, etc. will need to be considered in the design elements. The design scope may need to include heated guideways/running services, heated power rails, heated switches, heated control cabinets, a potential snowplow device on the front of the train car design, and other weather-related concerns such as high winds to ensure the APM can be utilized every day, as needed.

Of course, security is a major component of any concept, particularly if the APM is outside of airport purview where there is no screening. These systems will require working closely with local police and security specialists to develop a viable solution.

Also, maintenance is another oft-overlooked piece of APM development. Key considerations that must be evaluated include maintenance shop requirements, parts storage, service bays, communications, maintenance time frames when the APM is unavailable, etc.

Then there’s longevity and redundancy to consider. In our experience, we recommend that the design life of the APM systems should be set at 50 years or more. The trains themselves will likely be 25 or up to 30 years. As for redundancy, the rubber tire systems that require switching between the tracks makes failure mode redundancy much more achievable than the typical cable drawn system.

As well, most maintenance activities will be accomplished at night/early morning hours, when service is slow. Typically, one track will remain open and run a shuttle train as needed, while the other track is checked for concerns and/or repaired where necessary.

For additional redundancy, a bus service should be established as a backup plan to a full-service outage, such as an unforeseen full loss of power or a major system failure.

Fortunately, there is also help from industry resources.

An Industry Guide

Relevant APM standards and even some state regulations (e.g., Colorado Conveyance Act) can guide every project owner and consultant to cover all the critical factors of APM development.

One of the most wide-ranging standards related to APMs is the ASCE 21-21 Automated People Mover Standards. Originally developed in the mid-1990s, ASCE 21-21 was prepared by the Automated People Mover Standards Committee of the Standards Council of the Transportation and Development Institute of ASCE. It has been reaffirmed every three to four years since then, building on lessons learned from projects around the world and technology advancements.

This standard establishes the minimum requirements necessary to achieve an acceptable level of safety and performance for an APM system. It covers design, construction, operation, and maintenance of APM systems.

While this standard is not required (like a building code), it is a powerful guide to best practices and has been foundational to many APM developments over the years. Topics include requirements for an APM in passenger operation, security, safety, system verification/demonstration as well as operation, maintenance, training and operational monitoring.

This standard is a great place to start for an owner to assess all the components that lead to APM success. Owners might also consider requiring bidders to follow that standard.

The Importance of Specificity

One of the fundamental elements to every successful APM is around the importance of specificity of project specifications.

Without specificity, bidders may interpret requirements differently and propose solutions that vary dramatically, making fair evaluation difficult. Given broad scopes, bidders are likely to bid only on the exact requirements in the spec to be competitive in terms of cost. However, after the contract is awarded, change orders become more likely if the original spec lacked clarity, which could introduce delays, increased costs, and scope creep.

As well, with a limited specification, vendors are not able to anticipate and bid proactively on needs beyond what is explicitly required in the spec. Therefore, the client risks not getting everything they want or need from the system.

By taking the time upfront to be clear about all technical, operational, and performance needs, the client sets expectations properly and ensures the solution delivered will meet all their requirements.

To that end, define performance metrics like reliability, capacity and response times as specifically as possible (e.g., 99.9% on-time arrival rate). Lock down key specifications that will impact costs like the alignment, number of vehicles, and berthing/station configurations. Include a section focused on maintenance and contingency planning requirements. Require expandability/flexibility in the design to accommodate future growth over the long lifespan of the system.

Clearly defining all needs upfront will help ensure the right solution is procured while also establishing evaluation criteria for proposals.

Finally, when considering the procurement of an APM System, look for a partner that has the experience to identify potential scope gaps throughout the process to minimize potential change orders, and keep the contract on time and within the budget—and one that has the expertise to keep your APM on track.

About the Authors

Douglas Baird has over 20 years of hands-on experience delivering APM projects worldwide, from Denver to Madrid to Houston. Through his leadership roles both within a system supplier role, as well as system oversight directly for the airport, and his long-standing involvement on the ASCE 21-21 Automated People Mover Standards committee, Doug has helped establish industry best practices.

Steve Krier has more than 30 years of experience in operations, maintenance and repair service delivery. For 19 years, he maintained the Automated People Mover (APM) system at the Denver International Airport in successive roles of increasing responsibility. Steve’s experience and knowledge includes HSE management, customer interface and relations, manpower resource management, staff supervision and training, financial management, and commercial awareness. He was an active member of the inaugural State of Colorado Advisory Board (Conveyance Program) as well as a key member of the subcommittee for APM Systems during the development of conveyance. Steve’s technical background and problem-solving capabilities drive resolutions in complex situations. He has collaborated with stakeholders from joint ventures, clients and consultants, and successfully delivered results to sophisticated projects.