Miles Per Gallon vs. Miles Per Hour: Debating Speed Limits in an Oil Crisis
Key Takeways
- Driving slower saves fuel as well as lives, with every 5 mph over 50 mph adding meaningfully to fuel costs.
- Speed limits have five dimensions: designed, posted, observed, caught, and fatal. Effective policy must address all of them.
- The 1970s precedent shows that crisis-era speed reductions can prove surprisingly durable, lasting decades beyond the original trigger.
- A crisis can create a rare platform for change, but only if public opinion has reached the threshold where unpopular measures feel necessary. Has this crisis reached that point for lower speeds?
- Local democratic legitimacy matters: speed limit changes imposed from above are less likely to stick than those driven by communities themselves.
- Political capital is finite; governments should weigh whether speed limits are the best use of it compared to higher-impact transport reforms.
- The case for lower speeds is not really in dispute; the debate is about timing, process, and strategy.
Next Steps
Should lower speeds be part of your response to the current oil crisis?
Introduction
When the oil crisis hit in the 1970s, governments reached for lower speed limits. It worked then, but does that playbook still apply today?
In this week's blog, Sam Sklar and Russell King go head-to-head on whether reducing speed limits should be part of our response to the current oil crisis. Sam makes the case for slowing down, arguing it saves both lives and fuel. Russell pushes back, questioning whether now is really the right moment to act.
For (Sam)
Sam's arguments can be found on his blog here.
Against (Russell)
Slower speeds offer many advantages: improved safety, more walking and cycling, and better fuel efficiency. Evidence from urban areas shows that lower speed limits make very little difference to overall journey times, so the case for them is strong in principle.
The key question, however, is one of timing. Is this current oil crisis the right moment to introduce lower speed limits? I would argue it is not.
During the 1970s oil crisis, the United States and other countries reduced speed limits to cut fuel consumption. The change proved remarkably sticky; it took until the mid-1990s for the US legislation to be repealed. So why not take the same approach today?
The first reason is that the current crisis, at least so far, is less severe than that of the 1970s. The earlier crisis brought long queues at petrol stations, a far more oil-dependent global economy, and fewer alternatives to Middle Eastern supply. That scale of disruption gave governments a powerful mandate for change; people could see the problem and were willing to accept tough measures. Today, the situation has not reached that threshold. Imposing blanket speed reductions now risks provoking a public backlash, leading to a swift reversal and, worse, lasting damage to the broader case for lower speeds.
The second reason is democratic. Who should set the speed limits on local roads? My view is that this should largely be a matter for local communities and their elected representatives (perhaps as a former Councillor, I was always going to take that perspective). Locally-driven decisions carry greater democratic legitimacy and are far more likely to be sustained over time. Where a community is receptive to lower speeds, local authorities have a genuine mandate to act. But where support is clearly absent, there is no social licence to impose such changes, and without that licence, they will not last.
The third reason is one of political priority. Good governance is about choices. Governments have limited political capital and bandwidth, and they can only fight so many battles at once. Lower speed limits risk becoming a lightning rod for controversy, consuming the goodwill needed to deliver more impactful reforms, such as expanded public transport and pop-up cycle infrastructure, that Sam and I have discussed elsewhere in this series. Those measures will deliver far greater long-term benefits than the modest fuel savings that come from reduced speeds. Governments must choose their battles wisely, and this should not be one of them.
In short, now is not the time for blanket lower speed limits. The public case for them is not yet strong enough to command broad support; decisions about local roads should be made locally; and politicians would do better to spend their political capital on transport reforms with greater and more lasting impact.
Conclusion
Sam and Russell agree on more than it might first appear. Slower speeds are safer, better for the environment, and, as the current crisis makes plain, better for fuel efficiency too. The real disagreement is one of timing, democratic process, and political strategy.
Sam's case is grounded in the evidence: the relationship between speed and safety is well established, and an oil crisis provides a rare moment of public receptiveness to change. Russell's counterpoint is a pragmatic one, that poorly timed or top-down interventions risk backlash, eroding the very public support that lasting reform requires.
Perhaps the most honest conclusion is that both can be right. The case for lower speeds is strong; the question of when and how to implement them is where good policymakers must exercise judgment. If the current crisis deepens, the window for bolder action may open. Until then, the debate Sam and Russell have laid out here is exactly the kind of thinking our cities and communities need more of.