As I was driving around New York state recently, I witnessed a problem looming in the shadows: queuing at direct-current (DC) electric vehicle fast-charging stations. And earlier this month, I stumbled upon a LinkedIn post highlighting the same budding dilemma. 

Historically, the long lines peak during the holidays when DC fast-charging stations see a rise in charging sessions — especially in states such as California, where 16 percent of all new vehicle sales are electric, compared with 9 percent in other EV-leading states such as New York or Oregon and even less elsewhere. However, this queuing issue may become a more common occurrence and potentially a nightmare for drivers as more EVs hit the road.

As background, in the world of EV charging, DC fast-charging stations, also known as Level 3 charging stations, generally charge an EV from 0 to 80 percent in 15 to 30 minutes, depending on the station type and vehicle.

The way I see it, the queuing issue breaks down into three buckets: 

• Not enough charging stations
• Getting drivers on their way 
• Managing the queue

Let’s explore each point, review what exists as a solution and suggest some alternative routes. 

Not enough charging stations

Deploying more DC fast-charging stations is one simple and obvious solution to the queuing problem. More fast-charging stations would lead to additional charging opportunities, which would then decrease the chance of overcrowding. As of January, 28,250 public DC fast-charging stations exist in the U.S. 

That number is expected to rise rapidly as states deploy more charging stations through the National Electric Vehicle Infrastructure (NEVI) Formula Program to achieve President Joe Biden’s goal of 500,000 chargers by 2030. 

Additionally, Tesla has officially committed to adding 3,500 Supercharger locations with compatible chargers for non-Tesla EVs, and it’s already deploying some chargers. These efforts work in tandem with the company's plan to double its overall charging network by 2024.

Anthony Lambkin, Electrify America’s vice president of operations, agrees that more charging stations could help address the problem, but they aren’t the only solution.

"One simple way to address the problem is through more EV charging education, especially around charging etiquette, so drivers are aware of charging best practices, including queuing. And customers who use the Electrify America app will know what stations have chargers available for better trip planning."

Getting drivers on their way

Charging providers use idle fees to discourage vehicles from idling in a spot after charging is complete. In the basic sense, an idle fee is what the provider charges a driver for the additional time they remain plugged into the charger after reaching 100 percent state-of-charge.

Tesla’s approach to idle fees only kicks in when the entire station location is at 50 percent capacity or more. Other companies also charge idle fees, but enforcement seems sporadic. For example, Out of Spec reviews tested a lack of idle fee enforcement by Electrify America and confirmed that the company was not charging fees, even though it was supposed to. When I asked Lambkin why this is happening and if it's still ongoing, I didn't get a clear answer: "We are currently evaluating various approaches to encourage customers to move their vehicles after they have finished charging and [in a way that] doesn’t compromise the customer experience." 

In addition to actually enforcing idle fees, charging providers could also increase the charging cost once a vehicle reaches the infamous 80 percent state-of-charge threshold. Once a battery hits 80 percent, the charging speed significantly reduces, which can further increase queuing issues. Adding this component would be different from how major charging companies such as Electrify America and EVgo charge for using their stations — per kilowatt-hour. However, the idea isn’t entirely off the beaten path from something like time of use rates.

But wait, what about reserved charging?

The queuing problem may worsen as more charging providers and automotive companies explore the idea of reserved charging at scale. Through this approach, a driver can reserve a charging station as they approach it to ensure it's available for them to charge. 

Once a battery hits 80%, the charging speed significantly reduces, which can further increase queuing issues.

However, I’m not entirely sure how reserving charging stations will fix EV charging queuing issues. For example, this British tabloid captures how emotions can run high as people wait to charge. Now imagine having a perfectly usable charging station just waiting in reserve mode because a driver hasn't arrived yet. Extrapolate that out, where dozens of stations are just waiting to be used, at any given location, and it doesn't make sense to plug in only for a short duration of time before the reserved time slot begins, and you can see some issues developing. 

Managing the queue

Remember when I told you I witnessed a charging pileup firsthand? This is when that anecdote becomes relevant. As I was charging at a Tesla Supercharger station, the lot quickly reached capacity. Yet cars continued to pull into the station to wait for a charge. 

The situation was stress-inducing even as an observer. I witnessed drivers parking their vehicles to face the charging EVs, often taking up one to two parking spaces in the process. Once a charging station opened up, it seemed like a mad dash in acceleration from the poorly organized queue, creating a huge safety issue for pedestrians and other drivers. 

Charging providers and automotive companies, working through in-vehicle navigation systems, could dynamically push drivers to different charging locations as one approach to relieve the pressure.

Tesla’s Trip Planner already does this in some form, which has also helped the company improve fast-charging speeds by 30 percent over five years. However, clearly it’s not a perfect solution, as stories continue to pop up of Tesla drivers clogging up Supercharger locations. 

Other automotive companies offer various in-vehicle navigation features that route drivers through charging stations. But in my opinion, nothing is close to Tesla. I’ve heard many stories very similar to the one here (jump to the 5:00 mark for the piece on EV charging) where the in-car GPS routed a driver to a broken charging station.

Another alternative solution is the idea of a virtual queue. Monta, an EV operating platform, offers a version of virtual queuing. But it appears the business model is geared toward businesses with workplace charging, and it feels more like a reservable EV charging station model, as discussed earlier. 

In an ideal world, the EV industry adds a dynamic lever to the charging model. As you approach a full charging location, your EV (of any make) connects to the charging location and enters itself into a virtual queue, with entry to the queue dependent upon close geographical proximity. Drivers then park in an available normal parking spot, and only when prompted, proceed to plug in and charge. If a driver attempted to charge before their turn, the chargers would simply not communicate with the vehicle. This could allow a driver to be more relaxed, park their vehicle in an available parking space and wait their turn.