Meaning literally, “right traffic day,” Dagen Högertrafik, or “Dagen H” (H day),
was the day in 1967 that the country of Sweden managed to successfully switch from driving
on the left-hand side of the road to the right.
Not a spur of the moment decision, the Högertrafikomläggningen (“The right hand traffic diversion”) had
been planned for years prior to implementation, in recognition of the inherent problems that
arose by the fact that among the nations of Continental Europe, Sweden was the only country
where people still drove on the left.
(If you’re curious why, see: Why Some Countries Drive on the Right and Some Countries Drive
on the Left.)
In addition, the architects of the plan tapped into the widespread perception that having
the steering wheel on the left while also driving there caused more head-on collisions.
Regardless, switching to the right was not a popular idea among Swedes, and when the
idea was first floated in 1955, only 17% of the populace approved the change.
However, realizing that in the late 1960s nearly 10,000,000 cars would cross Swedish
borders one way or another, and knowing that that number was predicted to double by the
early 1970s, Swedish leaders decided to make the switch.
Voting for the Statens Högertrafikkommission (HTK) in 1963, the Swedish Riksdag instituted
a commission that established a four-year program to make the change and educate the
populace.
Consulting psychiatrists on how to get public buy-in for the plan, the government sponsored
campaigns that placed the Dagen H logo on everything from underwear (including advertising
with scantily clad models wearing said underwear) to milk cartons.
They even sponsored a song contest where the Telstars had the winner with Håll dig till
höger, Svensson (“keep to the right, Svensson.”)
The switch necessitated the replacement or retrofitting of nearly every traffic light,
bus (the doors were switched to the right-hand side), bus stop (which had to be moved across
the street), road line and headlamp.
At the time a trend had begun to arise to have headlamps direct their light to be slightly
brighter on one side to illuminate the bordering ditch or sidewalk side of the road better.
The rising popularity of this increased the pressure to make the switch sooner than later
as those who had these headlamps made for left-hand driving, but driving on right hand
roads, would reportedly blind oncoming drivers (with the extra light now shining directly
into oncoming traffic instead of the side of the road) and vice-versa as cars crossed
the borders.
The final cost of Dagen H has been estimated at around £40 million in 1967 money or about
£648 million today.
During the preparations for the single-day switch, the new traffic lights were wrapped
in black plastic to keep from confusing drivers before the big day, and the road lines, which
were painted white instead of the traditional Swedish yellow, were covered in black tape.
(One imagines it was a banner year for a certain tape manufacturer.)
In addition, prior to H day 12,000,000 notes were distributed to citizens, and 130,000
tilted H signs were deployed along Sweden’s roads, to remind drivers of the switch.
On Sunday, September 3, 1967, for most of the country, all non-essential traffic was
banned from 1 to 6 a.m.
In these places, at 4:50 a.m., all vehicles that were allowed to drive had to completely
stop, and then carefully change to the right-hand side of the road.
At precisely 5:00 a.m., traffic was allowed to resume, at which time Swedish drivers experienced
what Time magazine called “a brief but monumental traffic jam,” that happily resolved relatively
quickly.
In some of its largest towns, including Stockholm and Malmö, the ban on non-essential traffic
began as early as 10 p.m. the night before, and lasted until 4 p.m. that Sunday, in order
to give workers time to re-do the intersections.
In total, about 8,000 officials and 150,0000 volunteers were deployed that weekend, either
to convert traffic signals and lines, keep the peace, or to assist pedestrians at dangerous
intersections.
Anxious to try out the latest thing, hundreds of thousands of drivers poured onto Swedish
streets that Sunday once their ban had been lifted.
Surprisingly, there were only 157 accidents, with only 32 causing any personal injuries,
and just “a handful of these were serious.”
The following Monday’s rush hour traffic went relatively smoothly all things considered,
and the 125 reported traffic accidents were fewer than the typical daily number of 130-198.
Many believe that the combination of the perceived risk with a lack of familiarity made motorists
more careful than they’d normally be.
(For similar reasons, pedestrians are actually about 28% less likely to be hurt while crossing
a street if they illegally jaywalk, rather than cross at a crosswalk that doesn’t include
any additional signals like traffic lights.
The British, who also drove on the left (and still do), observed the switch intently, although
they remained unconvinced that a similar change would be in their best interests.
According to some estimates, moving to the right side in Britain at the time would have
cost nearly seven times what it cost Sweden, and, whether accurately or not, experts anticipated
even more switch-induced accidents would occur.
In addition, they noted that many countries, including Ireland, Malta and Cyprus, had their
own traffic eccentricities that worked just fine, even with tourists.
For instance, the people of Timor drive on the right in East Timor
Many early cars had the driver’s seat in the center of the car rather than on one side
or the other.
Gradually, car manufactures began putting the seat on one side or the other.
Some chose to put it on the side closest to the curb so that people could more easily
avoid scraping buildings, curbs, etc.
Other car manufactures would put it on the opposing traffic side to help reduce car to
car collisions, which would tend to be more deadly.
Many early American motorized vehicles actually placed the steering wheel on the right hand
side of the car, even though America used the keep-right rule.
This practice finally was put to an end largely due to Henry Ford; he preferred the left side
steering wheel so Ford cars featured this.
Due to their popularity, this effectively squashed the right hand steering wheel cars
in America.
According to research done in 1969 by J.J.
Leeming, keep-left countries have a much lower collision rate than keep-right countries.
It is thought the reason behind this is that most people’s right eye is their dominant
eye.
Thus, the right eye in keep-left traffic is the one closest to oncoming traffic and so
should reduce collisions.
Another theory as to why this might be is that most people are right handed, so when
driving a manual transmission car in a keep-left country, most people’s dominant hand is
on the steering wheel; this could help in a person’s ability to maneuver accurately.