Traffic lights, prohibition, and Al Capone

I’m obsessed, you’ll hardly be surprised to hear, with traffic lights. I go hunting around cities for vintage control cabinets, ancient pneumatic vehicle sensors, elderly induction loops, historic duct covers, and period guard rails. I’ve been known to take university students on field trips to explore traffic control infrastructure, much to their entirely reasonable bemusement. In a future post, I’ll even explain what Benny Hill has to do with the history of traffic lights. But today, I want to talk about prohibition.

First, please enjoy this Pathé newsreel film from 1933. Turn your speakers right up. The film depicts a brand-new vehicle-actuated traffic control installation at London’s Trafalgar Square being ceremonially switched on (yes, that was a thing). Listen carefully near the start and you’ll hear the clicking of relay switches in the control box as vehicles drive over pneumatic sensors in the junction.

There were two main types of traffic light system in the 1930s. The first, like the one depicted in the newsreel, was demand-based. This was what the Ministry of Transport loved, and they were the guys who held the purse strings. Vehicle-actuated signals at busy junctions, with pedestrian crossings included in the junction layout operated on demand by pushbuttons.

But the system had its critics. As the system responded to demand, rather than working on fixed time cycles, drivers and pedestrians faced unpredictable delays at light-controlled junctions and sometimes these waits could be lengthy. This led to pedestrians taking risks by crossing against the traffic, and drivers choosing to use side-streets to avoid hold-ups.

Enter one Herbert Alker Tripp, the Metropolitan Police traffic commissioner of the time and a man even more obsessed than me with traffic lights. And Alker Tripp hated the Ministry of Transport’s vehicle-operated signals. In 1935 he wrote to an official to say:

“the whole picture looks to me to be not a cohesive system, but a widely scattered sprinkling of independent installations, which might indeed ultimately prove mischievous rather than helpful. What we want to secure is regular passage for pedestrians; and pedestrians must not be left guessing as to the intervals between the successive stoppages of the traffic or the length of time that will be given to them for passage. From that point of view vehicle-actuated signals are far from ideal in inner areas.”¹

Tripp had a different idea, and he was thinking big. He wanted to reshape London’s entire streetscape. He had a plan to line every street with metal guard rails. Every 150 or 200 yards, he proposed building a pedestrian crossing protected by traffic lights and, ultimately, automatic barriers, like the ones at railway level crossings. Then he wanted to pass a law that prohibited pedestrians from entering the roadway except at the crossings—and even there only when the lights and barriers permitted it.

Tripp’s traffic signals were different from the Ministry’s favoured type. His would work on the so-called “flexible-progressive” system, which was time- rather than demand-based. Each signal in a distinct area would be timed to synchronize with others on a route to create a green wave of light phases progressing along the road at a fixed speed—say, 17 miles per hour. Drivers travelling at the system speed should expect to find all the lights at green as the journey progressed.

In effect there would therefore be platoons of vehicles moving at a constant speed, separated by regular gaps in the traffic coinciding with the red phases. The pedestrian phases at each crossing would be timed to occur during these gaps—reducing stoppages of traffic for pedestrians—and the gaps would also assist traffic turning into the main road from side streets. The result would be consistency of flow, predictability of waits for both vehicles and pedestrians, and the minimum of hold-up.

In 1935, getting little support from the Ministry for his London-wide scheme, Tripp decided to set up a 1.5-mile experiment on a single busy trunk road in east London, the East India Dock Road.

He got his guard rails. They were just over three feet high and installed twelve inches from the edge of the kerb, allowing vehicles to drive close to the edge of the carriageway without fear of striking pedestrians and thus, it was said, making better use of road space. Gaps were provided at bus and tram stops, side roads, and garages, and businesses requiring goods-loading were provided with hinged sections under their lock and key for use during deliveries. The full installation was completed by September 1936, and it was the country’s first ever large-scale installation of guard-rail technology.

As it turned out, Tripp didn’t manage to get the complementary pedestrian crossings or traffic lights installed by the time the Second World War broke out three years later; still less the change in legislation he wanted. But it’s worth looking at where the thinking for his scheme came from, because aspects of it still control our urban lives today.

Traffic policing in the motor age

The rapid and widespread adoption of motor cars after the First World War profoundly reshaped the relationship between the police and the public. The roads were now full of vehicles travelling much faster than in the solely horse-drawn days, and the historian Clive Emsley has observed that “By the early 1920s the use of the law to control motor vehicles was jamming the magistrates’ courts and creating friction, hitherto unknown, between the police and the middle classes.”² Keith Laybourn and David Taylor said that “the seemingly narrow issue of the regulation of traffic raised wider questions of individual freedom and, much to the concern of the police, brought ordinary, working-class constables into contact (and conflict) with members of the middle classes, who previously had held a positive, if somewhat patronising, perception of the British bobby.”³

Alker Tripp had long been clear about the role the motor car had played in reshaping the relationship between the police and the public. “Motor-car law,” he said in 1928, four years before his promotion to traffic commissioner, “has brought a new stratum of the public into frequent relations with the police. The area of contact, and of potential friction in consequence, increases daily.”

He went on, “the individual constable enters on task already handicapped by having to some extent lost his reputation as a monument of stolid and tolerant commonsense and a barrier against interference with individual liberty. He is too often regarded as a busybody, a stickler for trifles ... The police must vindicate anew their quality in the public eye.”⁴

Given this background, Tripp’s guard-rail-and-pedestrian-crossing scheme might seem likely only to increase friction between citizen and cop. But Tripp was a sophisticated thinker. While he believed that “promiscuous pedestrian crossing will ultimately have to be prohibited,” he didn’t want police officers to be responsible for the prohibition. He wanted to use technology to embody traffic control in the public itself.⁵ It would be the lights and railings that kept pedestrians and traffic in order, not human agents of the state.

Predictability, a sense of systematic order, and centralized, absent control were key to Tripp’s scheme. That’s why he favoured time-based traffic signals, rather than the vehicle-actuated signals favoured by the Ministry of Transport. And that’s why he set up his experiment on the East India Dock Road.

In Tripp’s mind was the grid-plan city, like New York, Chicago, or Detroit. Grid plans offered multiple routes to bypass congestion and, in their regularity and order, lent themselves more readily to control. By the 1930s, US city grids had come to make great impressions on European specialists, and Tripp was one of them. He could not, of course, reshape London’s street plan literally. Instead, he proposed, with his time-based traffic lights, to replicate in London the moving platoons of vehicles and pedestrians that occurred in the gridded streets of the USA.

There was a bigger issue. Tripp, and the Metropolitan Police, didn’t have control of London’s streets. They shared it: with the Ministry of Transport, with the patchwork of local authorities, and with all sorts of interest and pressure groups, including Chambers of Commerce, the Automobile Association, and the Pedestrian’s Association. By introducing American methods to London’s streets, Tripp was attempting to smuggle in their police forces’ city-wide traffic control—and he had seen what he wanted at first hand.

A Chicago road Tripp

Tripp was appointed traffic commissioner in 1932, and one of his first tasks had been to visit the USA and Canada to study how they controlled their traffic. Over 20 days in October 1934, he visited New York, Boston, Detroit, Chicago, Toronto and Montreal, and when he got back to his London desk, he wrote a report for his police colleagues and the Ministry of Transport detailing his findings. It’s a hell of a read.⁶

Tripp’s promotion had come just one year after a change at the top of the Metropolitan Police, with the retirement of the “gentle” commissioner, Julian Byng, and the arrival of the “autocratic, intolerant” Hugh Trenchard, as David Ascoli has described them.⁷ Tripp himself brought a new style. His predecessor, Frank Elliott, had been described as a “kindly” and “much-liked” old policeman.⁸ Tripp, by contrast, was “forceful and cogent in conference and a born fighter, he was impatient of compromise and delay and he both gave and took hard knocks.”⁹

In many ways, Tripp’s 1934 visit to North America was symbolic of a harder-edged approach to match the changing times. Tripp’s rhetoric was about public safety, not individual liberty as had been paramount in a previous generation. His was a more American (interventive, controlling) police model, replacing an older British one of consent and freedom. In his report of the 1934 trip to America, we can discern disturbing influences that were to further shape his approach.

In Tripp’s eyes, the difference between America and England was the difference between prevention and cure. “One is conscious,” he began in his report, “of what appears to be a constant solicitude on the part of the House of Commons for the motorists’ interest—a solicitude which arises largely from the desire to protect personal liberty.”

He went on, “the Americans seem in one important particular to have been clearer-sighted than ourselves: they have consistently relied upon prohibitions intended to prevent bad habits of driving (e.g. by speed limits, stop-streets, etc.) instead of merely leaving dangerous driving to be dealt with after it has occurred.”¹⁰

He called for immediate action: “Such action lies along the lines of (i) physical safeguards—traffic lights, duplicate carriageways, railings ... and (ii) a code of exact law (based on the advice of traffic experts to the exclusion of interested parties) which is firmly, rigidly and exactly enforced by a more specialised police organisation with the help of courts which are more alive to the public danger and less concerned with the liberty of action of the motorist.”¹¹

Much of the report involved statistical reporting of accident rates and so on. But he also offered verbatim accounts of confrontations between local police and the citizenry that throw a frank light on methods of control in 1930s America. In fact, the report’s potentially controversial nature was recognized by Hugh Trenchard, who, asking for it to be made confidential, observed, “I do not want to see extracts from the report published in every newspaper. I think it would have a very bad effect if some of the sentences in it were taken away from their context.”¹²

Tripp’s visit to America came just after the end of the Prohibition era. A country-wide ban on alcohol had been in operation from 1920 to 1933 and had led to a breakdown of respect for law-enforcement bodies, among other effects. Cities such as Chicago had become the focus of organized bootlegging gangs operating violent black markets, with Al Capone becoming an iconic figure in American criminal lore, and it is difficult to overstate the negative effects (though in many cases unintended) on American urban culture of this movement.

Tripp was in Chicago just months after Prohibition was repealed, and he made the following observations about what he saw as the breakdown of civil society in the city and others like it:

“it must be remembered that in these American cities (Chicago especially) there is a mixed population, much of which is drawn from the dregs of Europe. Of the murders in Chicago about 30% are negroes killing negroes, and, as the Police put it, ‘when a negro gets a drop of liquor into him he kills. He will kill for anything. He will kill for an electric light globe, a cigar, or really for nothing at all.’ Another 10% are Italians killing Italians, and the majority are gangsters killing gangsters, or criminals, criminals. The risk to life run by the ordinary white man who behaves himself and manages to keep clean of rackets is much lower than might be inferred from the statistics.”¹³

Apart from forcefully articulating the era’s typically racialized discourse, what this translated to was a “bold and rather extreme policy,” in Tripp’s words, of active policing.¹⁴ He described night-time police cruises he’d ridden along with, in which people deemed suspicious were stopped, searched and, if still considered suspicious, arrested and taken to the police station for questioning.

His trip was ostensibly to learn about traffic control but, as he later reported, it was these night-time experiences that gave him a thrill. “I confess that I found it most entertaining,” he recalled. “There was a spice of excitement and adventure about it which was not to be denied.”¹⁵

In one account, he described an episode in the early hours of the morning when the cruiser in which he was riding took a call to attend a robbery-with-violence on a drug store in a working-class African-American neighbourhood. Once on the scene, the police sergeant and Tripp went inside to take down details from the owners, a black couple. Here’s how Tripp described the incident in his report (the word near the end was fully spelled out in Tripp’s report):

“We found a negro and negress behind the counter looking very anxious and worried, for they were afraid of being implicated. Particulars were taken. After he had finished, the Sergeant turned to me. ‘Gee’, he said in a tone of supreme contempt, ‘they’ve only rolled a n_____ for a couple of dahlers, and they call it rahbry’.”¹⁶

There was also endemic corruption of both the police and courts as a result of Prohibition. Police corruption took the form of large-scale political interference in the service, individually corrupt officers, corrupt practice in compacts with criminals such as Al Capone, and the overlooking of offences to obtain political advantage. The last type was particularly relevant to the traffic service, where widespread traffic offence ticket-fixing took place.

The tension here was about individual liberty versus public order, and it’s clear that Tripp had some sympathy with the American approach. He began by remarking as follows:

“one of the main reasons for the results produced in America is that the Police (armed with appropriate laws) contrive to make the motoring public ‘toe the line’ (so to speak) in a way that we never have succeeded in doing. Speed is lower and more uniform and vehicles keep line better. That effect is not produced by exhortation of Press campaign; it is produced partly by mechanical control, but especially by intensive law enforcement.”¹⁷

Then he expanded on his theme, stating that the police in all countries had been “put to the test by the sudden menace” of motor traffic in the first thirty years of the twentieth century, and some had reacted better than others:

“American institutions and methods seem to have reacted more freely and better than our own, which have proved too inflexible and conservative. We appear to have shown less adaptability of mind; and as a result we have by contrast failed to a greater degree. To say this is not of course to decry the British character or to exalt the American by contrast. Undue quickness of reaction may easily lead to instability; the fiasco of Prohibition is a case in point.”¹⁸

Segregation on the streets of London

Following his return from America in 1934, Tripp made the following observation about exclusion in the context of traffic in US towns:

“Regulation of traffic is all in favour of the private car; commercial vehicles are rigorously excluded from many of the main traffic arteries in towns, while in the country the parkways, which are specially constructed motor roads, exhibit notices ‘No buses, no trucks, no commercial traffic.’”¹⁹

Tripp became a prolific writer on matters relating to traffic and the public. Throughout his work, there is a strong rhetoric of exclusion, and it was pedestrians who were most clearly in his mind.

The term he consistently used for the separation of pedestrians from vehicles was “segregation,” giving a new meaning to a term that had been used by his predecessors, from the early 1920s, to mean separating horse-drawn traffic from motor vehicles, or freight and public-service vehicles from private cars.

In Tripp’s influential 1938 book Road Traffic and Its Control, he described two forms of pedestrian separation, namely place-segregation and time-segregation, as follows:

“In the case of new roads required for the needs of wheeled traffic, pedestrians can be excluded altogether. In the case of existing roads, footpaths provide the means of segregation, so far as pedestrians proceeding longitudinally are concerned—more especially if guard-rails are added. For pedestrians crossing the road, however, a system of place-segregation (by bridge or subway) is very costly, and the less straightforward plan of time-segregation must generally be invoked.”

In the latter case, pedestrians and motor vehicles needed to share the same physical road space but not at the same time, and crossings protected by traffic signals provided the segregating technology. However, care needed to be taken, cautioned Tripp, to balance the needs of pedestrians to cross the road with the need for what he called “vehicular fluidity” in order to prevent the “virtual immobility” of motorists.²⁰

Tripp had been presenting the notion of pedestrian segregation since his appointment as traffic commissioner. In 1933, in front of the Institute of Transport, he made a bold set of claims about the unfairness of the road scene towards motorists:

“Pedestrians demand the right to use any part of the footway or carriageway at their discretion. The footway is forbidden ground for vehicles; but the carriageway is not forbidden ground for pedestrians ... Vehicles are herded into droves on each side of the road, and are ordered about by police officers and traffic signals and made to use one way streets and so forth; pedestrians are completely free agents.”²¹

The solution, he said, was that “steps should be taken wherever possible to segregate vehicular and pedestrian movement, and that in the case of arterial routes, the segregation should be absolute.”²²

This was a vision based on classification and the apportionment of value to citizens and their use of the road. Tripp said, “The first step towards solution of the whole problem of the design of streets and traffic requirements must be a critical analysis of the demands of the various classes of road users, and a strict assessment of them in order to determine which are legitimate and which excessive and therefore inadmissible.”²³

The cop in the machine

In other words, who deserves to use London’s streets?

It was a knotty problem in the mid-1930s, and it’s at the heart of a lot of today’s fractious political discourse. You might consider railings along the sides of roads as entirely mundane: a simple road safety technology. Pedestrian crossings and traffic signals, the same. They feel unproblematic. But to understand them we have to understand the contexts in which they were first installed. These contexts include 1930s concerns over policing overreach, over personal liberty, over the role of the state, over criminality and prohibition, and over segregation and the classification of citizens.

I have more to say about the segregation aspect of this story in my book, Spaces of Congestion and Traffic: Politics and Technologies in Twentieth-Century London. I’ve hinted at the racial element in this post and I expand on it more in the book. I also talk more about Alker Tripp’s influence on postwar town planning, and how the modern city owes a great deal to his ways of thinking. If you want to read it and can’t easily find a copy, message me.

And this stuff is important. I know I joke about my traffic-light obsession, hahaha I’m such a nerd, but it is important. Big political notions about liberty and public order, ideas that came from and made sense in the 1930s, in Prohibition-era Chicago and a world of classification and segregation, are working on us today, because the ideas were embodied in technologies, and those technologies are still in operation (albeit a lot of London’s railings have been removed in the last ten years or so).

In some cases it’s literally the same kit that was installed decades ago. Look hard enough, like I do, and you can still find pneumatic vehicle-actuated roadway sensors, and they’re still connected to the traffic light network. They still make relays click. They still tell us to stop or go and we generally obey.

1. TNA: MEPO 2/6748, letter, Tripp to Archibald Matheson (Ministry of Transport), 30 April 1935.

2. Clive Emsley, ‘“Mother, What Did Policemen Do When There Weren’t Any Motors?” The Law, the Police and the Regulation of Motor Traffic in England, 1900–1939’, The Historical Journal 36, no. 2 (June 1993): 357.

3. Keith Laybourn and David Taylor, Policing in England and Wales, 1918–39: The Fed, Flying Squads and Forensics (Basingstoke: Palgrave Macmillan, 2011), 9 and 106.

4. Alker Tripp, ‘Police and Public: A New Test of Police Quality’, Police Journal 1 (1928): 533.

5. The National Archives (hereafter TNA): MEPO 2/6748, file note by Tripp, probably sent to Arthur Dixon (Home Office), 3 May 1935.

6. TNA: MEPO2/5937, Report by H. Alker Tripp, Assistant Commissioner, on Visit to America, October, 1934.

7. David Ascoli, The Queen’s Peace: The Origins and Development of the Metropolitan Police 1829–1979 (London: Hamish Hamilton, 1979), 219 and 227.

8. The Times, 27 March 1939, 14.

9. The Times, 23 December 1954, 9.

10. TNA: MEPO2/5937, III:2.

11. TNA: MEPO2/5937, III:11-12.

12. TNA: MEPO 2/5937, memorandum, Hugh Trenchard (Commissioner) to Tripp, 18 December 1934.

13. TNA: MEPO2/5937, II:6.

14. TNA: MEPO2/5937, II:7.

15. TNA: MEPO2/5937, IV:1.

16. TNA: MEPO2/5937, IV:7.

17. TNA: MEPO2/5937, IIA:5.

18. TNA: MEPO2/5937, III:1.

19. TNA: MEPO2/5937, I:7.

20. Alker Tripp, Road Traffic and Its Control (London: E. Arnold, 1938), 136–37.

21. Alker Tripp, ‘The Design of Streets for Traffic Requirements’, Journal of the Institute of Transport 15, no. 2 (December 1933): 76.

22. Tripp, 80.

23. Tripp, 84.