Lincoln Tunnel Research Articles

Geospatial Analysis in Responding to a Nuclear Detonation Scenario in NYC: The Gotham Shield Exercise

Abstract In April 2017, the Centers for Disease Control and Prevention (CDC) participated in the Gotham Shield Exercise, led by the Federal Emergency Management Agency (FEMA) and in collaboration with other federal agencies to test the federal, state and local government’s ability to respond to an improvised nuclear device (IND). With active engagement from CDC leadership, 266 scientific and support staff from across the agency participated in the Gotham Shield exercise. The scenario involved a 10-kiloton detonation near the Lincoln Tunnel in New Jersey. This nuclear detonation scenario provided CDC with the opportunity to test some of the all-hazards tools the agency uses during response to other national or international emergencies, such as Geographic Information Systems (GIS) and mapping tools, and apply these tools to a nuclear emergency. Geospatial analysis associated with real time data can provide near real time information for individuals and entities associated with response and recovery activities. This type of analysis can provide timely data in regard to maps and information used to properly place staging areas for Community Reception Centers (CRC), mass care locations, and other medical care and countermeasure related services. Maps showing locations of power loss, such as locations of lost or inoperable main electrical grid and substations, combined with real time data on where power is available provides valuable information for first responders and emergency managers as well as responders engaged in communicating critical public messages to affected populations in these areas. By using real-time information, response officials can direct the response, allocate scarce resources, aid in coordination efforts, and provide a more efficient means of providing critical public health and medical services. The results of the exercise highlight the importance of using geospatial analysis for response planning and effect mitigation before, during, and after a public health event of this magnitude, and the value they represent in informed decision making.

Reinforcement-Learning-Based Cooperative Adaptive Cruise Control of Buses in the Lincoln Tunnel Corridor with Time-Varying Topology

The exclusive bus lane (XBL) is one of the most popular bus transit systems in the U.S. The Lincoln Tunnel utilizes an XBL through the tunnel in the AM peak period. This paper proposes a novel data-driven cooperative adaptive cruise control (CACC) algorithm that aims to minimize a cost function for connected and autonomous buses along the XBL. Different from existing model-based CACC algorithms, the proposed approach employs the idea of reinforcement learning, which does not rely on accurate knowledge of bus dynamics. Considering a time-varying topology, where each autonomous vehicle can only receive information from preceding vehicles that are within its communication range, a distributed controller is learned real-time by online headway, velocity, and acceleration data collected from the system trajectories. The convergence of the proposed algorithm and the stability of the closed-loop system are rigorously analyzed. The effectiveness of the proposed approach is demonstrated using a well-calibrated Paramics microscopic traffic simulation model of the XBL corridor. The simulation results show that the travel time in the autonomous version of the XBL are close to the present day travel time even when the bus volume is increased by 30%.

Turning Hospital Beds into Votes: Frank Hague and His Jersey City Medical Center

On October 2, 1936, President Franklin Roosevelt emerged from the Lincoln Tunnel to the cheers of an estimated 200,000 people. The citizens of Jersey City, New Jersey were there to not only greet their president but to show their loyalty to the mayor of the city, Frank Hague, who had given all city employees a paid holiday from work to attend the event. FDR was on his way to the dedication of the city’s new hospital, The Jersey City Medical Center. In his opening remarks, the President stated, “very happy to come here to take part in the dedication of this, the third largest medical institutional group in the whole of the United States”. The facility would go on to become one of the leading medical institutions of the era and a breeding ground for endless political patronage. It would provide top-quality cradle-to-grave healthcare to the city’s citizens free of charge as long as they voted the “right” way. Ironically, FDR closed his speech with these words: “Mayor Hague, his associates, and the people of this city have pointed the way for many other communities in the Nation. May they see and emulate the fruition of this splendid dream.” It was a dream that would become a nightmare.

Mason B. Williams. City of Ambition: FDR, La Guardia, and the Making of Modern New York.

During the 1930s, at a time when New Deal agencies dispensed an unprecedented amount of largesse to the nation's suffering cities, many Americans believed that New York City benefited far more than any other community. According to the conventional wisdom at the time, Mayor Fiorello La Guardia took advantage of his close personal relationship with Franklin D. Roosevelt to claim a disproportionate share of federal funds for his city. The president underscored this impression when he jovially said, “[La Guardia] comes to Washington and tells me a sad story. The tears run down my cheeks and the tears run down his cheeks and the next thing I know, he has wangled another $50 million out of me” (p. 206). Although Mason B. Williams disputes the notion that Gotham enjoyed such favoritism, he forcefully argues that the changes wrought as a result of the New Deal assumed critical importance in shaping modern New York City. The author correctly notes that many of the key elements in the city's current transportation network (especially those related to the automobile) can be traced to the Depression decade, including the FDR Drive, the Triborough Bridge, the Queens-Midtown Tunnel, Henry Hudson Drive, the Lincoln Tunnel, and La Guardia International Airport. Additionally, an impressive number of parks, schools, public housing projects, beaches, and numerous other government-built structures remain as part of the New Deal's enduring legacy. The infamous Robert Moses, an undeniably crucial figure in this epic public works saga, appears frequently in the book, working hand-in-hand with La Guardia and other city officials. For the most part, however, the author offers no assessment of the human costs necessary for the municipal improvements engineered by Moses and the various bureaucracies he administered.

The Long Road to Recovery: Environmental Health Impacts of Hurricane Sandy

Building contractor John Pierciey stands in the gutted interior of a 1950s-era home in Manasquan, New Jersey. Wallboard, two layers of wood flooring, a layer of felt—all of it had to be ripped out to rid the house of mold caused by Hurricane Sandy’s storm surge. “This is the sixth house I’ve gutted in a week,” Pierciey says. “Every one is different. You don’t know what you’re going to find until you take them apart.” Residents and volunteers keep warm by a fire barrel in the New Dorp Beach neighborhood of Staten Island, 5 November 2012. Power outages persisted through a cold snap that put temperatures in the single digits. So it is with the environmental health impacts of Hurricane Sandy. Every layer of society, every type of building, has felt the impact of the storm, which struck the U.S. East Coast on 29 October 2012. Incidences of death and illness, though small in number compared with some storms, have come in many forms, the effects still unfolding as time goes by.

Pay to drive in my bus lane: A stated choice analysis for the proposed Lincoln Tunnel HOT lane into Manhattan

This paper presents the findings from a stated choice (SC) analysis conducted in the context of proposed changes to the lane system in use for the Lincoln Tunnel crossing into Manhattan. Currently, the approach road (NJ 495) to the Lincoln Tunnel has six lanes, with three in each direction. During the weekday morning peak period, The Port Authority of New York and New Jersey (PANYNJ) operates a 2.5 miles exclusive bus lane (XBL) for traffic bound for Manhattan. The PANYNJ is considering creating, from existing lanes, a second XBL with the option for passenger vehicles to use it in return for an additional toll, in effect turning it into a high occupancy toll (HOT) lane. Such an approach to increase capacity and reduce congestion is unique nationally and this study looks at drivers' choices between using standard lanes, paying extra to drive on a HOT lane (the new XBL lane), switch to earlier or later departure times, or change their mode of travel. The analysis shows significant differences in the valuation of travel time savings between different population groups and also different departure time periods. The models also reveal a reluctance to change to other crossings, accept changes in departure time or switch to alternative modes.

Driven: Branding Derek Jeter, Redefining Race

Promoting the opening of the Museum of the City of New York's exhibit, The Glory Days: New York Baseball, 1947-1957, curator Ann Meyerson noted that for the first time since Jackie Robinson crossed the major league's color line in 1947, not a single African American player was likely to be included on either of the city's teams' twenty-five man rosters in 2007. Excluding, for the sake of argument, Mets prospect Lastings Milledge, now with the Nationals, where did that leave the captain of the New York Yankees, Derek Jeter? In a 2005 interview with the St. Petersburg Times, Jeter handled the subject of his race with characteristic, media-savvy care: My Dad is black, my Mom is Irish, and I'm Catholic, so I hear everything. I'm in New York and there are all different people, all races and religions. I can to everyone.(1) Since his 1996 rookie season, Derek Jeter has not only played shortstop for the New York Yankees, he has parlayed his ability to relate to everyone into what advertisers hope will translate into an ability to sell to everyone, working overtime as a pitching machine. Most of the products Jeter pitched before 2006 were ones generally associated with baseball and conventionally endorsed by its players--Nike sneakers, Gatorade sports drink, Ford cars and trucks, and a variety of breakfast and snack foods, including Ritz crackers, Post cereals, Skippy peanut butter, and, perhaps inevitably, Oreos. Not so surprisingly for one of the most generously compensated players in the game, Jeter also endorsed a financial institution, Fleet Bank. In his role as a well-known man about town, not altogether unfamiliar to the readers of New York's gossip columns, Jeter also appeared with his equally famous, generous compensator, George M. Steinbrenner, in a Visa commercial. Recently, however, Jeter has branched out beyond the expected, connecting his image to two very different brands. A short hop across town from the Museum of the City of New York, near the Morningside Heights home of Columbia University, Jeter peers out from a sign atop the subway entrance at 116th Street. Next to his readily identifiable image is the word DRIVEN. Driven is the signature fragrance of a line of products for men, introduced by Avon in April 2006 with a nationwide, integrated campaign including print ads, an interactive Web site, and, in the New York area, a variety of outdoor signage on busses and taxis, including the ad at the 116th Street subway entrance and others like it. According to Avon's Web site, Driven [reflects] the unique personality of one of the most driven men in America, Derek Jeter.(2) New York commuters of another stripe, returning home to North Jersey's more affluent suburbs from a lucrative day at the office in their well-appointed luxury vehicles, are also greeted by Jeter's giant visage, this time pitching Movado 800 series chronographs as they crawl down the helix from the Lincoln Tunnel to Route 3. Print ads bearing virtually the same image and accompanying copy have appeared in Gentleman's Quarterly, the New York Times Magazine, and other glossy publications aimed at a demographic, who, like the Yankees' captain, have a great deal of disposable income as well as a great deal of self-defined style. Jeter, who, along with New England Patriots quarterback Tom Brady, is the face of the brand, is also featured in a television commercial for Movado. Certainly, these ad campaigns target two separate and distinct groups of consumers, groups which, as early as the 1920s, the advertising industry differentiated as and class, respectively.(3) Despite the placement of an ad for Driven in GQ's December 2006 issue, the magazine's readers--the advertising industry's class--are probably not tying up circuits placing calls to their Avon ladies to order Driven. Neither is the fragrance, produced by a company that claims its brochures are distributed to over fifteen million customers biweekly, the epitome of mass when it comes to cosmetics, likely to be marketed heavily to luxury-conscious metrosexuals. …

Nearest Thing to Heaven: The Empire State Building and American Dreams (review)

Reviewed by: Nearest Thing to Heaven: The Empire State Building and American Dreams Roberta Moudry (bio) Nearest Thing to Heaven: The Empire State Building and American Dreams. By Mark Kingwell. New Haven, Conn.: Yale University Press, 2006. Pp. xii+235. $26. There is a specific moment on Route 3’s approach to New York City when the Manhattan skyline appears straight ahead, mirage-like, before disappearing as the road dips down to the Lincoln Tunnel. At center stage, the Empire State Building rises, its vertical chrome-and-nickel panels shimmering, its proportions striking among the cacaphony of sizes and shapes of the city’s structures—the ultimate symbol of New York. The building holds other claims to our imagination—we still marvel at a construction process that produced a completed building in a brief eighteen months (and under budget), growing skyward at a rate of four-plus stories a week, and the masterful photographs of Lewis Hine that documented it. Built at a moment of national financial crisis and self-doubt, the Empire State Building was a monument before birth, an urban-scaled demonstration of confidence and determination, of accomplishment against all odds, played out as street theater to an audience of literally millions. Its name, Empire State, claimed, and still claims, the building project for the city, the state, and the nation, lending a publicness to what is in reality a privately financed speculative office building. There is a substantial scholarship that provides architectural and cultural history of the Empire State Building’s conception, design, and construction, as well as a number of books for the general reader. Now, Nearest Thing to Heaven, the work of University of Toronto philosophy professor [End Page 1067] Mark Kingwell, joins these as an extended personal reflection on the significance of the Empire State Building in a post–September 11 world. Seven chapters with enticing titles—“Palace of Dreams,” “Image and Icon,” “Scrape the Sky,” “System and Structure,” “Still Life,” “Moving Pictures,” and “Empire”—suggest a thematic approach that addresses specific observations and theoretical considerations. Kingwell is clear that his project is episodic and not linear, likening his exploration to a kaleidoscope. Although kaleidoscopes arrange glass chips into unusual but relational wholes, Kingwell fails to use his own organizational strategies to relate, or even to reign in, diverse perspectives of the Empire State Building. He considers the building’s iconicity; its structure, both essential and hidden; the meanings of its construction and its materiality; its interior and exterior qualities and the disjuncture between these aspects; and the proliferation of its image in photographs, films, replicas, and trinkets. These observations provide excellent starting points for serious discussion, but too often personal narrative, or historical or theoretical digressions, lead away, rather than back to, those central points. For example, a discussion of skyscraper structure moves from ancient Egypt to nineteenth-century Paris and Henri Labrouste, but it does not bring the discussion to rest thoughtfully amid the structural and aesthetic skyscraper debates among American architects, engineers, and critics in the late nineteenth and early twentieth centuries. A sea of details and tidbits clutter rather than illuminate or intrigue. Part of the difficulty is embedded in the book’s underlying premise—that the Empire State Building was always better than the World Trade Center, that it was for a time overshadowed by the Twin Towers and has now regained its rightful place as Number One. If Kingwell had compared the two buildings, but without an agenda, he might have elaborated on their iconic selves (for one, iconic stature preceded construction, for the other, it emerged only after destruction), their respective abilities or shortcomings as workplaces and tourist attractions, and their role as participants in the spaces and skyline of the city. Instead, the text celebrates the Empire State Building while speaking disparagingly of the World Trade Center and of the entirety of European modernism, which Kingwell sees as the progenitor of the ubiquitous American glass-and-steel-slab skyscraper. The premise is problematic, and Kingwell’s explication of his antimodernist argument is fraught with factual errors and misinterpretations. For example, “Form follows function” was Louis Sullivan’s, not Frank Lloyd Wright’s, signature statement about skyscraper...

Analysis of Time-of-Day Pricing Impacts at Port Authority of New York and New Jersey Facilities

Time-of-day pricing policies provide lower toll rates during off-peak hours to reduce peak-hour traffic congestion. Time-of-day pricing was introduced at the Port Authority of New York and New Jersey (PANYNJ) bridges and tunnels on March 25, 2001, for E-ZPass users only. According to PANYNJ, 2 months after the implementation of the program, preliminary statistics indicated greater use of E-ZPass and some increase in off-peak travel. PANYNJ operates six toll facilities: George Washington Bridge, Lincoln Tunnel, Holland Tunnel, Bayonne Bridge, Goethals Bridge, and Outerbridge Crossing. In this paper, the relationship between toll price and travel demand at PANYNJ facilities was investigated with traffic data before and after the introduction of the time-of-day pricing program. Two main approaches were used. First, short-term elasticities were calculated with monthly traffic data from April through August for 2000 and 2001. Next, medium-term elasticities were calculated with monthly traffic data from May through August for 2000 and 2002. Seasonal variations in the database were also considered by performing related statistical tests.

Analysis of Time-of-Day Pricing Impacts at Port Authority of New York and New Jersey Facilities

Time-of-day pricing policies provide lower toll rates during off-peak hours to reduce peak-hour traffic congestion. Time-of-day pricing was introduced at the Port Authority of New York and New Jersey (PANYNJ) bridges and tunnels on March 25, 2001, for E-ZPass users only. According to PANYNJ, 2 months after the implementation of the program, preliminary statistics indicated greater use of E-ZPass and some increase in off-peak travel. PANYNJ operates six toll facilities: George Washington Bridge, Lincoln Tunnel, Holland Tunnel, Bayonne Bridge, Goethals Bridge, and Outerbridge Crossing. In this paper, the relationship between toll price and travel demand at PANYNJ facilities was investigated with traffic data before and after the introduction of the time-of-day pricing program. Two main approaches were used. First, short-term elasticities were calculated with monthly traffic data from April through August for 2000 and 2001. Next, medium-term elasticities were calculated with monthly traffic data from May thr...

Methodology for Siting Ambient Air Monitors at the Neighborhood Scale

In siting a monitor to measure compliance with U.S. National Ambient Air Quality Standards (NAAQS) for par-ticulate matter (PM), there is a need to characterize variations in PM concentration within a neighborhood-scale region to achieve monitor siting objectives. A simple methodology is provided here for the selection of a neighborhood-scale site for meeting either of the two objectives identified for PM monitoring. This methodology is based on analyzing middle-scale (from 100 to 500 m) data from within the area of interest. The required data can be obtained from widely available dispersion models and emissions databases. The performance of the siting methodology was evaluated in a neighborhood-scale field study conducted in Hudson County, NJ, to characterize the area’s inhalable particulate (PM10) concentrations. Air monitors were located within a 2- by 2-km area in the vicinity of the Lincoln Tunnel entrance in Hudson County. Results indicate the siting methodology performed well, providing a positive relationship between the predicted concentration rank at each site and the actual rank experienced during the field study. Also discussed are factors that adversely affected the predictive capabilities of the model.

War and Nature: Fighting Humans and Insects with Chemicals from World War I to Silent Spring (review)

Sci-fi fans who recall the 1957 film The Deadly Mantis, in which soldiers trap and gas the movie's star in the Lincoln Tunnel, will readily appreciate the theme of this engaging book. Edmund Russell aims to show that "war and the control of nature coevolved: the control of nature expanded the scale of war, and war expanded the scale on which people controlled nature." "More specifically," he continues, "the control of nature formed one root of total war, and total war helped expand the control of nature to the scale rued by modern environmentalists. This book makes that argument through a case study, the interaction between chemical warfare and pest control in the twentieth century" (pp. 2-3).

The oasis

The idea of an evening in Manhattan had been savoured by both of us for weeks. The Upper East Side location was especially attractive to my wife because, during our brief courtship, it had been the scene of many exhilarating evenings filled with the intensity of a new relationship and the elan of that very special part of the world. The recent past had not been so sweet. The tension of the medical profession had begun to spill over into our life at home, creating an underlying insecurity previously rare in the medical profession. Thus, an evening of good food, good friends, and good conversation was just what the doctor ordered. Little did we know, as I pointed the car northward toward the Lincoln Tunnel, that the night and the day that followed would be full of revelations about the same profound issues from which I had hoped to escape.

The City as Motion Picture: Notes on Some California City Films

The City as Motion Picture: Notes on Some California City Films Scott MacDonald (bio) I’ve long recognized that, whatever pretensions I have about being an individual, for the most part my experiences are typical of large numbers of people; and therefore, if I say that in my lifetime I am aware of three distinct attitudes toward the American city, I do not mean to privilege my personal experience, but to recognize it as an index to the experiences of at least a portion of a particular generation. As I was growing up in Easton, Pennsylvania, during the 1940s and 50s (I was born in 1942), New York City was for me “The City” and our family trips into New York were the most exciting moments of my life. While I was thoroughly bored by what my family called “beautiful scenery” (expansive vistas of the mixture of farms and low Appalachian mountains characteristic of Pennsylvania and Virginia) I was fascinated by cityscapes —the more industrial, the better. The drive from Easton across New Jersey on Route 22 was foreplay leading to two climactic moments: the incredible industrial vista that opened between Newark, Elizabeth, and Jersey City; and the sight of Manhattan from the Pulaski Skyway. For me, and for my father, New York City and its industrial surround were a human creation beyond art, [End Page 109] and whatever pollution and environmental devastation we were vaguely aware of seemed not only inevitable, but romantic. For my father, whose hopes of a college education vanished the year he graduated high school when the Great Depression hit, the distant, wavering flames burning off petroleum fumes in Elizabeth were candles lit in honor of America’s postwar industrial boom and the smoke that darkened the sky was incense—even the horrific stockyard smell near Secaucus (if we were entering Manhattan via the Lincoln Tunnel) was humorous: “P.U. Secaucus,” we’d laugh. Of course, the conclusion of our journey, and the greatest product of America’s industrialization, was New York City itself. It was the largest and, we assumed, the most dynamic city in the world. That seemed obvious from the panorama we could see from the top of the Empire State Building and from the awesome golden cavern of the Radio City Music Hall, two of the inevitable goals of these trips. This consciousness of New York City as the great American product of successful, democratic industrialization remained with me through my adolescence and into my twenties, when history and my personal circumstances revealed a new sense of the American city. During my six years living in Gainesville, Florida, as a graduate student at the University of Florida, I couldn’t help but wonder what Gainesville residents did for a living. Except for the university itself, there didn’t seem to be any substantial employers, no big factories—and yet every year I was there, Gainesville grew by a considerable percentage. It wasn’t until much later that I realized the obvious: that Gainesville’s “industry” was the building of Gainesville itself (when I arrived in 1960 the population was less than 30,000; as of 1990 the city had tripled in size, and Alachua County had passed 180,000). Increasingly, my sense of the city as a product—epitomized by Manhattan—gave way to a new sense of the American city-in-process, growing larger and suburbanizing, so that increasingly it made sense to rank cities in terms of the population of the metropolitan [End Page 110] areas of which they were a part. If I remained snobbishly loyal to the idea of New York as the best an American city could be, I couldn’t help but recognize that the “new,” expanding metro areas in Florida, Texas, Arizona, and especially, California, were where the real city-building energy was, and as the metropolitan area of Los Angeles passed the metro area of Chicago, I was forced to realize that it might be only a matter of time before the New York area was no longer the biggest urban space, even in the United States. In recent years, the relationship of the expansion of cities and their resulting transformations...

Concentrations of Volatile Organic Compounds in the Passenger Compartments of Automobiles

In-vehicle concentrations of selected gasoline-derived volatile organic compounds (VOCs) and formal- dehyde were examined on 113 commutes through suburban New Jersey and 33 New Jersey/New York commutes. Overall median concentrations were lowest in a typical suburban commute, slightly higher on the New Jersey Turnpike, and highest in transit through the Lincoln Tunnel. Median in-vehicle concentrations of benzene, ethylbenzene, m&p-xylene, and o-xylene were 14, 6.8, 36, and 15 μg/m3, respectively. One vehicle, with a carbureted engine, developed malfunctions that caused gasoline emissions within the engine compartment during driving, resulting in the gasoline-derived VOC concentrations in this vehicle being much higher than in the properly maintained fuel-injected vehicle, particularly for the low ventilation extreme. The highest in-vehicle benzene concentration measured during these malfunctions was 45.2 μg/m3. The air concentration in the vehicle driven in tandem was a factor of 25 less (1.8 μg/m3).

Non-methane organic composition in the Lincoln Tunnel

Measurements of the non-methane organic carbon (NMOC) are reported for the Lincoln Tunnel from a 1982 study. The NMOC levels in the tunnel were a factor of approximately 4 lower than those found in a similar study performed in 1970. This decrease probably reflects reduced vehicular tailpipe emissions due to the utilization of catalyst-equipped vehicles. Acetylene concentrations in the tunnel decreased to a greater extent than many of the other major individual hydrocarbon compounds during the 1970-1982 period. This decrease was attributed to the preferential oxidation of acetylene by the catalytic converter installed on vehicles beginning with the 1975 model year. New NMOC compounds and sum of NMOC compounds to acetylene ratios are reported. These ratios are useful in the estimation of vehicular tailpipe emission contribution to NMOC levels observed in urban and industrial areas. 24 references, 6 tables.

Estimation of traffic variables using a linear model of traffic flow

Estimation of traffic velocity and the number of vehicles on adjacent sections of a limited access highway is examined. The method evaluated is based upon application of Kalman Filtering Methods to a linear state variable model of traffic flow. The estimator utilizes velocity and flow measurements at selected points along the highway. The flow measurement is a nonlinear function of the state variables and necessitates linearization about the one step ahead prediction of the state (extended Kalman Filter) or about nominal values of the state variables. It is shown that performance using Lincoln Tunnel data is comparable in either case to that of methods previously reported and provides a substantial savings in storage requirements. Also demonstrated is the fact that flow at an internal measurement point may be deleted from the observation vector without a serious effect on performance. This would arise, for example, if control of traffic were to be exercised at such a point.

Application of Kalman Filtering to the Surveillance and Control of Traffic Systems

The methodology of the discrete-time, extended Kalman filter is applied for the estimation of densities and the control of critical traffic links. The methodology is tested using traffic data obtained at the Lincoln tunnel of New York City. Two algorithms are tested, one involving density estimation alone and one combining density estimation with a formalism for the determination of optimal control. The results indicate that the first algorithm gives very good density estimates. The second algorithm yields a less accurate density estimate, but has the advantage over the first that it is amenable to an analytical optimization investigation.

Real-time traffic flow optimization

Discussed are methods underlying the real-time monitoring and controlling system of a critical traffic link. Algorithms were developed for recognizing the length patterns of vehicles passing over detectors and using these for precisely computing traffic density in several sections of the Lincoln Tunnel. Vehicle control was adjusted by the system to optimize tunnel throughput.

Vehicular tunnel traffic-flow control

A description of an operational vehicular tunnel traffic-flow control system is presented. Using photoconductive cells as vehicle detectors in the Lincoln Tunnel South Tube and a fixed logic hardware controller to activate traffic signals and signs at the tunnel entrance, traffic is metered in a manner which results in less congestion. The vehicle detectors use wall-mounted high-intensity light sources aimed at a cell which is located below a hole in the tunnel roadway. The cell is hard-wire connected to the logic controller. The controller, using discrete solid-state components, determines the number of vehicles between two points in a tunnel lane; in addition the controller calculates the speed of each vehicle at both points. Using these parameters, the controller decides if the entering traffic-flow rate should be lowered. If a decrease in the rate is warranted, amber traffic signals and a sign which states "pause here-then go" is then energized. When the threat of possible congestion is alleviated, the entrance controls are automatically de-energized by the controller. A comprehensive traffic-flow control and stoppage-detection system now being implemented is also discussed. This system will employ four small-scale digital computers working in pairs at both the Holland and Lincoln Tunnels. Basic raw data will come from both induction-loop vehicle detectors and photocell vehicle detectors arranged in alternating pairs at seven points in each of the ten traffic lanes comprising the two facilities. Output will consist of control signals to entrance traffic devices, as well as alarms designed to draw the attention of facility personnel to one of nine or more television monitors per tube showing the area of a detected stoppage.