Over the past couple of weeks, the latest conflict in the Middle East has become a material stress test for global energy supply chains.
The International Energy Agency (IEA) says flows of crude oil and products through the Strait of Hormuz have plunged from roughly 20 million barrels per day before the conflict to “a trickle,” and that Gulf producers have curtailed output by at least 10 million barrels per day. In response, IEA member countries have agreed to an emergency release of 400 million barrels from reserves, and the IEA also notes the conflict began on February 28, 2026.
In the UK, that global shock has been quickly felt at the pump and has triggered a market-monitoring response. The Competition and Markets Authority has announced that it is stepping up scrutiny of petrol and diesel pricing and accelerating its review of fuel margins “since the conflict began,” explicitly watching for “rocket and feather” patterns as wholesale costs change.
Against that backdrop, a familiar question has resurfaced: when fuel gets more expensive, do drivers change how they drive—especially on motorways where small changes in speed can meaningfully change fuel consumption? The UK’s “eco-driving” guidance is well-known and widely shared; the open question is whether we can see its adoption at scale in real-world driving data during this latest price rise.
What Drivers Are Being Advised to do to Reduce Fuel Spend
UK motoring organizations have repeatedly pointed drivers towards “eco-driving” behaviors—particularly smoother acceleration, fewer speed changes, and avoiding excessive speed.
In its guidance for economical driving, the RAC states that “the speed you drive at is arguably the most influential factor affecting fuel consumption,” and it recommends gentle acceleration and using the highest appropriate gear while staying within speed limits. In parallel “how to save fuel” advice emphasizes maintaining a steady pace on motorways and avoiding unnecessary acceleration (including the nuance that cruise control can help only on flatter sections where it holds a constant speed).
The AA gives drivers a concrete rule-of-thumb on why speed matters: it notes that driving at 70mph can use up to 9% more fuel than at 60mph (and up to 15% more than at 50mph).
This guidance is directionally consistent: if price pressure is strong enough—and if drivers believe it will last—some portion of drivers may respond by easing back a few mph on free-flow motorway segments, trading time for fuel savings.
Our Hypothesis, and What Happened When Prices Spiked in July 2022
Our working hypothesis is straightforward: when fuel costs surge, some drivers adopt eco-driving advice, and we can detect that behavior as lower free-flow motorway speeds.
This matters because “free-flow” is where driver choice is clearest. UK transport statistics describe free-flow speeds as those observed where external constraints on driver behaviour (such as junctions, sharp bends, hills, and speed enforcement cameras) are not present. In data science terms, it’s the closest we can get to answering: “How fast would drivers choose to go when the road is clear?”
At INRIX, this concept aligns closely with our “reference speed” baseline: the typical speed a road segment can sustain under uncongested, free-flow conditions, which is used to anchor many downstream mobility metrics.
We have already seen this behavior once in recent history.
In July 2022, UK forecourt prices hit record territory. Official weekly pump-price statistics published by the Department for Energy Security and Net Zero show average petrol at 191.55p per liter and diesel at 199.22p per liter in the week commencing 4 July 2022—levels that remain the high-water mark in the modern data series. This price spike was also highly salient in the public narrative of the time: the Office for National Statistics reported that fuel prices rose 2.9% between June and July 2022 and were 43.7% higher than a year earlier (the highest annual rate in the constructed series back to 1989).
During that July 2022 price shock, INRIX analysis observed a 4 mph reduction in the average speed of cars on UK motorways under free-flow conditions (i.e., on segments and at times when traffic was uncongested). This is exactly the signature we would expect if a meaningful share of drivers temporarily adopted “drive slower, drive smoother” fuel-saving advice.
Fuel Price Reality Check: July 2022 versus March 2026
Before interpreting behavior, it helps to quantify the price signals drivers are reacting to—and to compare the size and speed of the shock.
What the Official Data Says About the July 2022 Run-Up
DESNZ’s weekly series (UK average pump prices) shows that, in the four weeks leading into the early-July 2022 peak:
- Petrol rose from 174.99p/liter (week commencing 6 June 2022) to 191.55p/liter (week commencing 4 July 2022): an increase of +16.56p (about +9.5%).
- Diesel rose from 184.94p/liter to 199.22p/liter over the same period: +14.28p (about +7.7%).
In other words, the July 2022 environment combined two things that tend to drive behavioral change: (1) very high absolute prices, and (2) a rapid run-up visible week-to-week, which increased the likelihood that eco-driving advice felt immediately relevant.
What The Official Data Says About Early March 2026
In contrast, the latest DESNZ publication date for the weekly series is the week commencing March 9, 2026. The same dataset shows:
- Petrol at 135.67p/liter (week commencing 9 March 2026), up from 131.71p/liter on 23 February: +3.96p (about +3.0%) over roughly two weeks.
- Diesel at 149.01p/liter, up from 141.46p/liter on 23 February: +7.55p (about +5.3%) over the same span.
Another way to frame it: even after the recent rise, mid-March 2026 average pump prices remain around 56p/liter (petrol) and 50p/liter (diesel) below the early-July 2022 peaks in the same official data series.
Why We May Not be Seeing a July 2022-Style Motorway Speed Shift Yet
Given those comparisons, there are several evidence-backed reasons why the “slow down to save fuel” effect could be weaker, delayed, or harder to detect in March 2026 than it was at the July 2022 peak.
First, the price signal—so far—appears smaller in absolute terms. The early March 2026 rise is real, but (in official weekly averages) it is currently measured in single-digit pence per liter over a couple of weeks, not the sustained, high-visibility run-up into record highs seen in 2022. Behavioral change often has a “threshold” dynamic: until costs feel painful enough (or feel likely to remain high), many drivers may not trade travel time for fuel savings at motorway speeds.
Second, drivers may be uncertain about duration, because there is already significant coordinated intervention underway. The IEA’s emergency release of 400 million barrels is explicitly intended to address disruption and price spikes stemming from the conflict. If drivers expect prices to settle, the incentive to change habits immediately is lower—even if they notice prices rising.
Third, the vehicle mix is changing in ways that can dilute sensitivity to petrol and diesel prices. The RAC notes there are now over 1,850,000 fully electric cars on UK roads—around 5.4% of a ~34 million-car parc (using SMMT-based data). Meanwhile, electrified powertrains are no longer niche in new sales; in 2025, battery-electric cars accounted for 23.4% of new registrations, according to the Society of Motor Manufacturers and Traders. It’s a reasonable inference that as more journeys are made in EVs (and hybrids), the link between petrol/diesel price shocks and whole-fleet behavioral shifts becomes mechanically weaker—even if petrol/diesel drivers themselves are still price-sensitive.
Finally, timing matters. The conflict began on February 28, 2026, and—by mid-March—we are still early in the event window. It may take more than a couple of weekly price prints for behavioral adaptations (and their downstream speed signatures) to become statistically clear.
What We’ll Watch Next
“During the 2022 price shock we saw a clear, measurable shift in how fast people were travelling on freeflow motorways,” said Dr Nick Burgoyne, Head of Data Science at INRIX. “So far in March 2026, fuel prices have risen quickly—but they’re still well below the 2022 peak, and we’re not yet seeing the same stepchange in motorway speeds. We’ll continue to monitor the data and revisit this analysis if prices keep climbing or remain high for an extended period.”
As official weekly pump price data updates and the energy supply situation evolves, we will continue tracking free-flow motorway speeds alongside fuel prices—looking for whether a sustained period of elevated prices produces the kind of “eco-driving at scale” signature we observed in July 2022.