How adjusting speeds helps GO Trains beat the heat

Slower service on a hot day? It’s for your safety.

Jun 27, 2024

Nobody likes a delayed trip, especially on a hot, muggy day. So, imagine waiting on your platform, hearing an announcement about your train arriving late, and once it does, it’s going slower than you expect. Coupled with the heat, it can be a recipe for summertime sadness.  

But cooler heads prevail – those delays are designed with your safety in mind. 

Slowing our roll 

We pride ourselves on getting you where you need to go quickly, comfortably and affordably. During particularly hot days in our region, monitoring extreme heat and responding appropriately is pertinent to everyone’s safety.  

If you’ve ever touched a metal object on a hot day, you know how much heat they can absorb. So imagine the scale of thermal energy our entire track network takes in during a heat wave!  

Steel tracks on a hot, sunny day are prone to a condition called thermal expansion, which can cause them to soften and expand outwards – sometimes known as a sun kink. The impacts of climate change have particularly exacerbated the likelihood of these kinks happening, with climate scientists predicting even more severe weather events like heatwaves in the years ahead. 

At its worst, a sun kink can cause a train derailment. With safety being our top priority, we take every measure to mitigate risk. Rail temperatures are constantly monitored and when necessary, Metrolinx will issue a slow order, reducing a locomotive’s speed.  

Rail monitoring at operations centre

Experts are constantly monitoring the state of our rail network during extreme heat. (Metrolinx photo)

A slower train reduces the potential for issues when traveling over a hot rail and lowers the chances of a sun kink forming. It’s a practice used by rail agencies across the world in response to rising cases of extreme heat, especially in hotter areas like Texas or Florida.  

Our Network Operations Centre actively monitors rail temperatures, updating drivers in real time of the ongoing conditions. 

But sometimes the temperatures reach too high a point for a train to safely travel at all, and cancellations must occur. In those situations, Metrolinx will encourage riders to use one of our many GO Bus routes as an alternative.  

Latest updates on Hurontario LRT project

New track is pre-heated prior to installation to improve its high-temperature performance. (Metrolinx photo)

Building for the future 

As we work to build and expand transit across the region, we do our best to be proactive to ensure our work remains resilient for generations to come.  

It’s projected that by 2050, the region will experience at least one day with a maximum temperature over 40 degrees Celsius, and the number of hot days over 32 degrees will quadruple. So, with guidance from experts including climate scientists, Metrolinx has developed a Climate Adaptation Strategy, outlining 40 key actions to keep our network running on time. But these aren’t just goals to aspire to.  

We’re already incorporating several of those actions into our construction guidelines. 

For example, when we lay new track, we pre-heat the steel to 37.8 degrees Celsius, resulting in a stronger metal that is less prone to warping and forming a sun kink.  

On top of that, we’re also taking mitigative action against other forms of climate change. 

Many GO Transit riders will remember the 2013 flooding of the Don River that saw over 1,000 passengers in need of rescue on a Richmond Hill GO Train. We’ve redesigned our track foundations, adjusted train operations and protocols and improved our weather monitoring to help ensure such an event does not happen again. 

GO Transit Network Status Screens

Our redesigned digital screens provide real time information across the network. (Metrolinx image)

Stay in the know 

When we adjust speed because of heat, schedule delays can happen. We’ll always do our best to let you know how long those delays may be, and the reason for it. You can always check our handy GO Tracker tool for real time updates, sign up for On the GO alerts, or visit our service updates page for more information on your trip’s status. And if you’re already at a station, you can always take a look at our digital screens for more.  

We know hot weather can be a challenge for everyone and sometimes issues do arise. But we’ll do our best to keep things on track. It’s all part of our promise to get you where you need to go, safely, comfortably and reliably. 


by Shane Kalicharan Metrolinx editorial content advisor