INTERSECTIONS

Refer to Chapter XI of the AASHTO Green Book - Chapter 8 (this has been edited and several pictures and tables do not appear on this page--for full version, please click below):
 

 BACKGROUND

 At grade intersections are one of the most critical and most complicated elements in highway design. The efficiency, safety, speed, cost of
 operation, and capacity of the highway system depend on the design of its intersections. Design criteria that are used to create the most efficient
 roadways are easily thwarted when that roadway meets up with intersecting traffic vying for the same limited roadway space. In urban and
 suburban areas in particular, the capacity of signalized intersections can effectively define the capacity of the highway system. Add the need
 safely to accommodate bicyclists and pedestrians with varying degrees of mobility, and the need to handle left and right turns, and the challenge
 faced by designers becomes even more complicated.

 The Basics of Intersection Design

 As stated in the AASHTO Green Book, the main objective of intersection design is to:

      ...reduce the severity of potential conflicts between motor vehicles, buses, trucks, bicycles, pedestrians, and facilities,
      while facilitating the convenience, ease, and comfort of people traversing the intersections.(p. 627)
 


Two kinds of intersections - at left busy, and at right, designed to limit thru traffic.

 INTERSECTION DESIGN ELEMENTS

 As is the case with other aspects of the highway design process, designers can use a wide range of intersection design elements in
 combination to provide both operational quality and safety. These include:

      Traffic islands to separate conflicting vehicle movements
      Street closures or realinements to simplify the number and orientation of traffic movements through an intersection
      Separate left and rightturn lanes to remove slowmoving or stopped vehicles from through traffic lanes
      Medians and channelized islands to provide refuge for pedestrians and bicyclists out of the vehicular traveled way.

 The following paragraphs summarize of primary intersection design guidelines.

 Angle of Intersection

 Crossing roadways should intersect at 90 degrees, if possible, and at no less than 75 degrees. Skew angles of 60 degrees or less may need
 geometric countermeasures, such as reconstruction, or traffic control, such as signalization.

 Horizontal and Vertical Alinement

 The alinement before and through an intersection must promote driver awareness, operate well under frequent braking, and be easy to drive, so
 that the navigational task is not too difficult. The Green Book has recommended values for the minimum stopping sight distance needed based
 on the design speed of the approach roads. The design of intersections should also incorporate provisions for intersection sight distance.
 

Medians

 Medians, either raised or painted, provide a physical separation between opposing traffic flows. They also provide a refuge area for
 pedestrians to wait at crossing locations. Medians are a standard form of channelization at rural roadways and urban street intersections
 carrying four or more lanes. There are two principal functions of medians specifically located at intersections:

      Separating opposing traffic flows
      Providing storage for vehicles making left and Uturns and vehicles crossing traffic and shielding pedestrians

 Another important benefit of a median in an urban area is that it offers a green space for trees and lowgrowing plant material. Careful
 consideration is needed, however, to select the proper location and type of plantings. Particularly in narrow medians, plantings can create
 maintenance problems, and trees can cause visual obstructions if not carefully located.

 Field studies and accident analysis provide similar findings on the operational and safety effects of the median width at intersections.' At rural
 unsignalized intersections, accidents and undesirable driving behavior decrease as the median width increases. In contrast, at suburban
 signalized and unsignalized intersections, accidents and undesirable driving behavior increase as the median width increases. 1 Median
 Intersection Design, NCHRP Report 375, Transportation Research Board, National Research Council, National Academy Press, Washington, DC, 1995.

 In other words, at rural unsignalized intersections, wider medians are preferable to narrower medians, unless signalization or suburban
 development is anticipated. At suburban intersections, the median should not be wider than necessary to accommodate the median leftturn
 treatment needed to serve current and future traffic volumes.
 

 Left Turn Lane Warrants and Design

 Leftturn lanes may provide added safety and efficiency at both unsignalized and signalized intersections. At signalized intersections, leftturn lane
 warrants are based on the magnitude of turning movements, accident experience, and general capacity relationships. The design values for
 leftturn approach tapers, turn bay tapers, and storage lane lengths are based on deceleration in the lane, storage in the lane, or a combination of
 both. At signalized intersections, the required length of storage bay is a function of signal cycle length.

 An example of a simple safety improvement is the addition of a painted leftturn lane at a rural intersection. This action not only reduces the
 potential for yearend accidents, but also provides drivers with a comfortable way to make a left turn. However, as is discussed in the Issues
 section of this chapter, the addition of a left turn lane can also affect resources along the side of the road or change the character of the road
 corridor. These are tradeoffs for designers to consider.

 RightTurn Lane Warrants and Design

 Depending on rightturn traffic volumes, accident history, highway speed, and availability of rightofway, rightturn lanes may be appropriate for
 some intersections. As with leftturn lanes, the taper and storage length design is based on deceleration, storage requirements, or both.

 Corner Radius Design

 The design for an intersection corner radius is based on the selection of a reasonable design vehicle for the specific location. Design vehicles
 can range from large (tractortrailer combinations) to small (private autos). There are a number of tradeoffs involved in this decision. Designing
 the corner radius for large vehicles requires more open intersections, and increases cost, and such intersections are more difficult to mark,
 signalize, and operate. In addition, the larger the dimensions of the radius, the greater the distance across the intersection from one side of the
 street to the other. This can make crossing the intersection much more difficult for pedestrians, particularly people who are elderly or have
 mobility impairments. Conversely, designing the corner radius for small vehicles can create operational problems should a significant number of
 larger vehicles have to use the intersection.

The actual radius or curb return design can be accomplished in one of four ways. Simple circular radius designs are the most commonly
 encountered design on lowspeed collector and local streets and in downtown areas. Alternative design methodologies include the use of
 symmetrical threecentered compound curves, asymmetrical threecentered compound curves, or simple radius curves with tapers. These
 designs better fit the paths of turning vehicles, thereby providing more efficient operations.

Traffic Islands

 Traffic islands, or channelization, represent one of the most important tools in the design of intersections. Islands can either be painted directly on
 the roadway surface or they may be raised. Painted or "flush" channelization may be used on highspeed highways to delineate turning lanes, in
 constrained locations, or where snow removal is a concern. Raised islands, with appropriate channels or curb ramps to accommodate users of
 wheelchairs or other related devices, should be used where the primary function of the island is to shield pedestrians, locate traffic control
 devices, or prohibit undesirable traffic movements.

 There are two basic types of traffic islandscorner islands that separate rightturning vehicles and median or divisional islands that separate
 opposing traffic flows on an intersection approach. Although islands in general provide a safe refuge for pedestrians, corner islands that
 separate rightturning vehicles in particular may make crossing intersections more difficult for pedestrians. These islands tend to widen the
 crossing distance. They can also make it more difficult for pedestrians to maneuver through the intersection, see oncoming traffic making right
 turns, and know where to cross, if the islands are not clearly delineated.

 Traffic Control Devices

 Traffic control devices are installed to designate rightofway at intersections and to provide for the safest and most efficient movement of all
 traffic, including pedestrians and bicyclists. The standards established in the latest edition of the Manual on Uniform Traffic Control Devices for
 Streets and Highways (MUTCD), published by the FHWA, must be followed to determine proper intersection control.


  NEW INTERSECTION DESIGN CONCEPTS

 In recent years, a new intersection design concept has evolved to provide an alternative to the traditional T, fourleg, and multileg intersections.
 This design concept is called a roundabout.

 Modern roundabouts are increasingly being recognized as design alternatives to the use of traditional traffic signals for intersections for arterials.
 They improve both safety and efficiency for pedestrians and bicyclists, as well as motor vehicles. So far, roundabouts have been built in such
 States as California, Colorado, Maryland, Nevada, Florida, and Vermont. These roundabouts are different from rotary or traffic circles that have
 been used in the United States for a number of years to give entering traffic the rightofway and encourage higher design speeds.

 The modern roundabout is designed to slow entering traffic and allow all the traffic to flow through the junction freely and safely. Unlike the older
 rotary design, entering vehicles must yield the rightofway to vehicles already in the circle. A deflection at the entrance forces vehicles to slow
 down. Traffic signals are not used, and pedestrians cross the streets at marked crosswalks.


Roundabout.

 The average delay at a roundabout is estimated to be less than half of that at a typical signalized intersection. Decreased delay may mean that
 fewer lanes are needed. Signalized intersections often require multiple approach lanes and multiple receiving lanes, which leads to a wider road.

 Perhaps the greatest advantages of roundabouts are their urban design and aesthetic aspects. Roundabouts eliminate the clutter of overhead
 wires and signal poles and allow signage to be reduced. They can be distinctive entry points into a community or mark a special place. The
 central island offers an opportunity for a variety of landscape designs, as well.

 ISSUES

 Each of the various components of intersection design can cause conflicts between the need for a safe and adequate design, on the one hand,
 and the need to minimize impact to the surrounding physical and human environments, on the other. In addition, the need to accommodate
 pedestrians and bicyclists can sometimes cause conflicts with the need to provide an efficient operating environment for vehicular traffic.

 Accommodating Pedestrians

 The safe and efficient accommodation of pedestrians at intersections is equally important as the provisions made for vehicles. Pedestrian
 movements should be provided for and their locations controlled to maximize safety and minimize conflicts with other traffic flows. Too often,
 pedestrians are a secondary consideration in the design of roadways, particularly at intersections in suburban areas.

 Solution

 For all but a few exceptions, pedestrian crosswalks should be located at intersections, should have appropriate curb ramps for accessibility, and
 should be clearly marked. Two parallel painted lines generally are not enough of a distinguishing marking. Often motorists confuse these lines
 with the stopping line and pull right up to the edge of the crosswalk. At a minimum, some type of striping or painting inside the crosswalk area is
 recommended to improve safety. Many cities and suburban areas have gone beyond this and added aesthetic treatments to their crosswalk
 designs, including use of the following:

      Distinguishing materials for crosswalks, such as brick, patterned concrete, and cobblestone
      Granite edging
      Colored pavement or solid painting of crosswalks.
 

Appropriate Corner Radius Design

 As mentioned earlier, there are many tradeoffs involved in the selection of the appropriate type and dimension of radius designs. Issues arise
 when all of the factors involved in the design decision are not considered. For example, if the primary intent of the intersection design is to move
 traffic through as quickly as possible, a higher corner radius would be selected. The dimensions of the corner radius send a message to drivers
 entering residential neighborhoods regarding the speed they can drive and should be designed with this in mind. Encouraging fast speeds
 around intersection corners into residential areas will undermine efforts to lower operating speeds within the neighborhoods themselves. In
 addition, faster speeds create an unsafe environment for pedestrians.

Addition of LeftTurn Lanes

 A common conflict arising from the use of channelization, or separation of traffic into definite paths of travel by traffic islands, medians, or
 pavement markings, is the addition of leftturn lanes. While there is no doubt that this can create a smoother flowing intersection, especially on
 twolane roads, the addition of a leftturn lane can significantly widen the width of the roadway, unless there is a median. This can change the
 character of an area, affect adjacent development or resources, and cause the road to be out of scale with its surroundings.

 Solution

 In cases where a leftturn lane is truly needed to improve safety and operational efficiency in a constricted rightofway, there may not be an easy
 solution to this issue. Sometimes the addition of leftturn lanes depends on new growth and development along the corridor. If the scenic, historic,
 or cultural resources are such that any additional widening would affect these resources, it may be that decisions made at the land use stage of
 planning should be reconsidered. Limiting development along the corridor will limit traffic volumes and the need for additional leftturn lanes.
 Another option is to lower traffic volumes on the roadway through other means, including creating or widening alternative routes.



Eyesore or gem: Brunel Roundabout 

I-BBC
BUILDING SITE
Five controversial buildings - should they stay or go? 
19 July 2007
 
The maxim of beauty being in the eye of the beholder is no more true than in people's estimations of modern buildings. To mark Architecture Week, the Magazine is taking some of Britain's most controversial buildings to task.

Of all the thousands of place-names in the UK, none have the quite the resonance and baggage of Slough, with its unkind poetic references.

The Berkshire town is now almost as famous for the Office, Ricky Gervais's sitcom, which offered glimpses of the town centre, particularly the Brunel Roundabout and nearby bus station.

Results are indicative and may not reflect public opinion

Now the roundabout, bus station and much of the surrounding area featured in the programme's title sequence are to be demolished as part of the £400m Heart of Slough project, which hopes to bring shops and new homes to a town centre long thought of as an urban planning dystopia.

Here Kevin Beresford, author and roundabouts enthusiast, expresses his dismay at the loss of an iconic site, while Slough councillor Dexter Smith says the town needs to slough off its ironic image as a great place for dismal buildings...
 



City wins a million to speed highway work
Whidbey News-Times
By Jessie Stensland
May 03 2006

The city of Oak Harbor took a step forward with plans to ease congestion and beautify the section of Highway 20 in the south end of town.
The Island County Regional Transportation Planning Organization awarded the city a $1 million grant this week to help fund a project to add lanes, three landscaped roundabouts and medians in the stretch of the highway between Beeksma Drive and Swantown Road.

The city is chipping in the required 13 percent match. In all, it’s enough money to fund engineering and environmental permitting for the project. Earlier this year, City Development Director Steve Powers estimated that the total cost, including construction, at $10.5 million.
 
“This is the first piece of the funding puzzle,” City Engineer Eric Johnston said in a press release. “It’s a big step in the right direction.”   The Island County RTPO had $1.76 million in federal transportation funds to divvy out for the 2006-2007 funding cycle. The organization provides funding for “regionally significant” transportation projects throughout the county.

The City Council chose to submit a grant request for the highway project instead of the municipal pier project because members felt the road project had a greater chance of winning funding. Apparently they were right.  Yet plans are complicated by the fact that the state Department of Transportation is responsible for highway improvements, but the state has limited dollars to spend on non-safety-related projects.

City staff has been working with — and urging along — DOT staff for years. Last year, the city and DOT completed a corridor study on the section of highway. The council unanimously approved the study, as well as a $300,000 contract for pre-design work.  According to a city press release, a central part of the highway improvement project is the creation of three landscaped roundabouts. “They will occupy space at the Beeksma Drive interchange, at Erie Street and at Swantown, where a roundabout will serve as a manicured welcome mat to the city,” the release states.
 
Traffic engineers at the state DOT tend to love roundabouts, which are intersections with one-way circulation around a center island, eliminating the need for a traffic signal. Studies have shown that they are safer, keeping traffic flowing more efficiently and are much less expensive than intersections with conventional traffic signals.  But roundabouts are different and new, which means they tend to be controversial until drivers get used to them.

Johnston said the city will likely hire a consultant for the design work later this summer. In the meantime, Oak Harbor officials will be looking for even more money to complete the rest of the project.  According to the city, the state transportation department will be working closely with the city to hunt for additional funds. City and DOT officials need to persuade elected officials in Olympia and Washington, D.C. that more dollars should flow to this vital stretch of highway that moves local traffic, tourists and freight at an existing volume of about 24,000 vehicles per day.

“This is a long-term project,” noted Johnston. “This is going to take several years before we get to the point where we’re ready to build.”




Roundabouts for all
Whidbey News-Times
By Eric Berto
Apr 23 2005

It could be like a junior high dance all over again.

People cautiously circle, not quite sure of what to do next. Finally, one person, then another gets up the courage to merge over to the other side. The result can be either a horrific accident or a smooth exit, finally reaching the goal.

If Oak Harbor and the Washington Department of Transportation install up to six roundabouts along Highway 20 between Swantown Avenue and Cabot Drive, it would do so over time, WSDOT Planning Engineer Eric Shjarback said at a Thursday evening open house.

“There’s a period of adjustment,” Oak Harbor resident Margaret Nichols said. “Sometimes it’s a long period of adjustment.”

Nichols said she has encountered roundabouts while on the east coast. She said that people need to be educated on the proper etiquette for navigating them.  A roundabout is a traffic control device that circles traffic in the same direction with multiple outlets to allow people to turn off.
Oak Harbor resident Jim Campbell had to learn how to drive in a roundabout while living for two years in Scotland. He said that the newness of them created a problem for him at first, but he was soon able to zoom about with the locals.

“There’s nothing worse than being stuck in the middle of a roundabout and not knowing what leg to go out,” Campbell said.  The roundabouts are being considered as a means to alleviate the growing traffic congestion problems in Oak Harbor. The study focuses on six intersection along Highway 20 between Swantown Avenue and Cabot Drive.

The city is spending $20,000 and the state is chipping in another $10,000 to find the best possible ways to ease the burden of traffic. Oak Harbor experiences between 17,000 and 20,000 vehicles traveling Highway 20 between Swantown and Cabot Avenue each day. WSDOT planners estimate that number will increase to at least 30,000 vehicles each day by the year 2030.

For the long term, the roundabouts ease congestion for a longer time than traffic signals, Shjarback said.  “If we are constrained to two lanes in each direction, the signals end up failing around the year 2020,” he said.  Roundabouts have moved their way to the top of the list for a variety of reasons, but tops on the list is safety, Shjarback said. By having people navigate an obstacle at slow speeds, people are more aware of their surroundings.

“The flow of the traffic is neat,” he said. “The traffic just kind of disappears.”
 




I-95 Northbound Up And Running;  Work Ahead Of Schedule On Damaged Span; South Side May Open Thursday
By LAURA WALSH, New London DAY, Published on 3/29/2004

Bridgeport— Construction workers whooped and cheered Sunday as a parade of cars, escorted by police, traveled on a northbound Interstate 95
overpass for the first time since a fiery tanker crash...


Northbound lanes to open soon; Rebuilding I-95 Temporary span to be rushed in
By DANIEL TEPFER dtepfer@ctpost.com 3-28-04
BRIDGEPORT - With a small cloud of dust and little fanfare, workers Saturday broke loose the last remaining chunk of the Interstate 95 overpass destroyed in a fiery crash.  The jagged chunk tumbled down to land on a huge pyramid of rubble on Howard Avenue.

"The southbound section has been fully demolished," said Art Gruhn, chief engineer for the state Department of Transportation. He said they will now begin laying a foundation for a temporary span to link the gap.  Earlier Gruhn announced some good news amid the disaster that crippled this major Northeast traffic artery. Extensive testing of the steel in the northbound lanes found them to be structurally sound. By midweek northbound traffic could be zooming past Bridgeport again.

However, he said because of the high volume of traffic that normally uses the turnpike, the reopened lanes would only be used for northbound traffic. Southbound traffic will continue to be diverted along local streets.  He said they are sticking to their original timetable that it will be one to two weeks before the whole span is open.

"It's looking very good for shorter rather than longer," he said.  Mayor John M. Fabrizi toured the construction site Saturday and said he was very encouraged by what he saw. He said he was especially happy to hear that the federal government will pick up the tab for the $11.2 million it will
cost to replace the span.  State officials estimate that 120,000 vehicles go over the section of the turnpike every day.

Traffic continued to clog local streets from Stratford to Fairfield as drivers sought a way around the closed turnpike.  State Police at Troop G in
Bridgeport reported that traffic volume on the Merritt Parkway was "extremely heavy" as motorists sought to circumvent the accident area.

"It was the equivalent of a heavy workday load all day long," Trooper Ken Damato, a spokesman for Troop G said.  "We had two small fender bender accidents on the Merritt northbound by exit 44 in Fairfield."

Compounding the extra traffic volume, state police had to contend with certain classes of drivers who apparently ignore signs on the Merritt .    "We had a serious problem with buses, tractor trailers and even recreational motor home vehicles getting on the Merritt between Stratford and Greenwich," Damato said. "First we stopped them, then we ticketed them and then we kicked them off the parkway."

The 18-wheelers are a double headache because what the drivers do to avoid shearing off the roofs of the trucks is "drive down the middle of the road," Damato said. "What they do is straddle the dotted line. If a tractor trailer does that and either hits an abutment or we observe them, then we also may issue them a ticket for reckless driving."

Scott Appleby, Bridgeport director of emergency management, said they had posted alternate travel routes on the city Web site at:
www.ci.bridgeport.ct.us

State police said an investigation is continuing into the crash Thursday night that caused all the destruction.  Despite the mass destruction caused by the crash, police said the 18-year-old Derby girl who caused it may only face a $95 ticket.  A tanker truck driven by 33-year-old Gilbert Robinson, of Galpin Street, Naugatuck, filled with more than 10,000 gallons of diesel fuel was traveling southbound between exits 26 and 25 shortly after 7:30 p.m. when it was hit from behind by a 1987 Toyota Corolla driven by Sarah Waddle, of Bank Street, Derby.

According to police and fire officials, as a result of the impact the tanker truck went out of control and slammed into the Jersey barrier on the right side. The truck slid along the barrier, ripping open the tank and spewing flaming fuel along a 200-yard path along the turnpike.  The truck came to a stop on the Howard Avenue overpass as a fireball more than 50-feet high engulfed the tank. Burning fuel poured between the cracks in the pavement igniting wooden boards on the underside.

The tremendous heat from the fire melted the steel girders under the bridge causing them to sag toward the roadway below.  The fireball melted high-voltage transmission lines stretched a hundred feet above the roadway carrying power from the Connecticut Resources Recovery Association plant.

United Illuminating spokeswoman Mary Ellen Cody said on Saturday crews began replacing the lines but they were not going to "re-energize" them until they got the OK from the crews working on the highway below.  The lines only affect power coming from the trash-to-energy plant and she said no UI customers are affected.

On Saturday, crews began laying a foundation around the gaping hole where the southbound lanes were to hold a temporary span.  The 85-foot-long temporary span, which had been held in storage in New Jersey by its manufacturer, Acrow, was being brought in pieces to the site. He said the span is three lanes wide and is made up of steel panels. The same type of span was used to replace temporarily the Mianus River Bridge after it collapsed on June 28, 1983.

"It's like a giant erector set, a lot of small pieces that have to be bolted together," he said. He said once the temporary span is put together it will be lifted onto the foundation on the southbound section of the overpass.  "It's not something we would want to use as a permanent structure, but it will be more than serviceable until we can put a permanent structure in place," he said.

He said the temporary bridge is rated to carry standard traffic and overweight vehicles will not be permitted over it.

"We are taking a project that would normally take a month to develop and doing it in a matter of hours," he said.  Gruhn stressed that this is a temporary fix and that a permanent structure will have to be built.  The original structure was under construction for three years and was nearly completed as part of a $113.2 million revamping of the highway between exits 24 and 26.  Gruhn said it could take a year and a half to replace the Howard Avenue overpass.


Bridge repair rushed;  Workers tackling damage from fire
by DANIEL TEPFER dtepfer@ctpost.com, 3-27-04
BRIDGEPORT
Delivering on a promise to work around the clock to reopen an Interstate 95 overpass destroyed in a fiery crash just 24 hours earlier, work crews Friday night began demolishing the structure.  When the buckled highway span is torn down, said Chris Cooper, a spokesman for the state Department of Transportation, "We will begin erecting a temporary bridge that is being trucked here."

Where and how the bridge will be erected and when it will begin carrying traffic will probably be determined this weekend. Northbound lanes may be
reopened as early as next week, officials hope.  Gov. John G. Rowland, standing Friday morning in front of the charred and twisted overpass at Howard Avenue, declared Bridgeport a disaster area and promised $11 million in state and federal aid.

"We have 120,000 cars traveling this roadway a day so our first priority is to get it reopened," he said.

Both sides of the busy stretch of I-95 were closed Thursday night by an explosion sparked by a collision between a tractor-trailer and a compact
sedan, causing the truck to slam into a highway barrier.  About 10,000 gallons of No. 2 fuel oil erupted into 50-foot-high flames that burned about three hours, destroying the highway's surface and melting part of its supporting structure. Remarkably, there were no serious injuries.

Gilbert Robinson, 33, of Naugatuck, was driving the hauler reportedly owned by Island Transport of Connecticut and New York, south of exit 26 about 7:30 p.m. Thursday, State Police said.  The truck was struck from behind by a 1987 Toyota Corolla driven by Sarah Waddle, of Bank Street, Derby, police said.

Waddle said Friday morning she was not injured. "I'm here with the cops now and we're going over everything," she said. No arrests have been made.  The southbound lanes were so severely damaged by the holocaust they will have to be torn down, and state engineers are trying to determine whether the northbound lanes are sound enough to be repaired and reopened.

Meanwhile, thousands of vehicles clogged major roadways from Stratford to Fairfield as commuters were forced onto local streets by detours around the accident scene, between I-95 exits 25 and 27.  Numerous minor accidents resulted from the traffic jam, city police said.  Mayor John M. Fabrizi pledged that police would be deployed in force to manage the traffic onslaught.

Trucks trying to use the Merritt Parkway as an alternate route were being stopped by police and sent to Route 8 and Interstate 84.  The heat of the fire that erupted when the tanker crashed melted the heavy steel girders supporting the overpass, causing it to sag about 7 feet toward
Howard Avenue below. As it cooled, the roadbed resettled, but the underbelly of the overpass was a mass of twisted and blackened metal.

Ronald Jantzen, a state Department of Transportation engineer, said the highway buckled and the recently constructed Howard Avenue overpass
sagged several feet.  The accident scene is in the I-95 corridor construction zone through Bridgeport, a massive rebuilding of the highway that began in 1996 and is projected to cost $400 million.

DOT engineers had earlier considered filling in the area under the wrecked bridge and building a new road surface on top of it, instead of replacing the bridge over Howard Avenue.  Instead, the replacement bridge will arrive on pallets in 10-foot by 6-foot sections. "It'll be kind of like putting an Erector Set together," said Cooper.

In reconstructing how the accident ended in an immense fireball, it appeared that Robinson lost control of the truck after being hit by Waddle's car and crashed into the Jersey barrier on the right side of the highway.  Bridgeport Assistant Fire Chief Fred Haschak said the tank then broke open in
two places.  The fuel oil, which is often used as home heating oil or as diesel fuel in vehicles, was apparently ignited by sparks as the truck scraped along the barrier, leaving a flaming trail for about 200 feet before it came to rest on the overpass above Howard Avenue.

Flames erupted from the top of the truck, creating a huge fireball that melted the insulation on power lines more than 50 feet above the turnpike.
Haschak said flaming fuel poured between cracks in the overpass, igniting wood framing under the bridge.  "It looked just like wood burning in a fireplace," he said.

Bridgeport firefighters, working with firefighters from Fairfield, Norwalk and Waterbury, were at the accident scene into the early morning hours Friday. Fire crews were able to prevent the blaze from spreading to several businesses near the highway.  A Bridgeport firefighter, suffering from an upset stomach from the strong fumes, was treated at the hospital and later released.

Bridgeport Fire Chief Michael Maglione estimated the fire burned at 1,800 degrees to 2,000 degrees, noting steel begins to weaken at 1,400 to 1,500 degrees.  Maglione said cars moving past the accident scene immediately after the crash created a mist of fuel oil in the air, which probably caused the fire. Home furnaces have a device to create such a spray, he said.

"When you put this type of a fuel in a mist form, if it finds a point of ignition it will light," he said.  Some of the diesel fuel found its way south into Cedar Creek, where the state Department of Environmental Protection set up booms to keep the spill from spreading into Long Island Sound.  Two men in a boat set out absorbent mats to collect oil along the creek.

"We laid out booms in big circles and we are making the circles smaller and smaller until we contain the oil and it can be removed by Connecticut Tank Removal," said John Aceto, emergency response coordinator for the DEP. "We expect to get a majority of it and the rest will be burned off by the sun."

Fabrizi said he was told the spilled fuel caused a half-million dollars in damage to boats moored in the creek.  I-95 has been the scene of many traffic disasters over the years, including a crash last year a short distance away that killed four Yale University students and the 1983 Mianus River Bridge collapse in Greenwich that killed three people.



Havemeyer residents back roundabout

Greenwich TIME
By Neil Vigdor, Staff Writer
Published March 28 2006

In a show of hands at a public hearing last night, a majority of Havemeyer Lane area residents signaled their support for a town-designed roundabout for the busy artery to help mitigate the impact of a new housing development.

Unveiled by the town's traffic engineer and planner at a special meeting of the Board of Selectmen, the roundabout would collect traffic from Havemeyer Lane to the north and south, North Ridge Road to the west and the entrance of a 195-unit housing development in Stamford to the east.

 The planned development, which is on the site of the former Cuisinart property at 77 Havemeyer Lane, has gained zoning approval from Stamford but has been tied up in litigation with Greenwich. Town officials, uncertain of the development's impact on the surrounding streets, want to have a hand in any changes to the traffic pattern.

"The roundabout would seem to be a very good safety measure," said Kathleen Saxon, a Northridge Road resident.

Saxon, like many of the 30 to 40 residents who attended last night's public hearing, called on officials to modify the design to include a one-way traffic restriction on her section of North Ridge Road so that cars would not be able to enter the cross-street from Havemeyer Lane.

But residents of some surrounding streets said the one-way restriction might increase traffic on their blocks, a warning echoed by town officials.

"Just remember, traffic is like water," Selectman Peter Crumbine said. "It's going to go somewhere."

First Selectman Jim Lash said the town would use the input from residents during its negotiations with the developer, Buckingham Starwood, in the legal case.

"We don't have a lot of leverage," said Lash, who cautioned that the roundabout design had to be accepted by the developer, as well as Stamford zoning officials. "In the end, this is in Stamford."



How would road charging work?  

By Tom Symonds
BBC transport correspondent  
16 October 2006

Road charging is the government's radical proposal to cut congestion, and pilot schemes are being developed. So what would it be like? A BBC experiment intends to find out.

This would be the biggest single change to the way we drive since the invention of the motorway.

It could change the way we think about using our cars.   It would certainly mean more of us would turn to that much-loved conversation starter - "so which way did you come?"

Because when and where you drive would become decisions with financial implications.  Road charging puts a price, possibly per mile, on roads depending on how busy they are.  This means a single-lane A-road heading into a busy city during the rush-hour is expensive to use. A quiet country lane on a Sunday is much cheaper, probably free.

It is slightly different from a congestion charge, such as the system in London, which you pay if you enter a central area of a city, and then at a flat daily rate.  The government likes road charging because it makes drivers face up to the true cost of road congestion.

Currently the tax we pay on petrol reflects only how far we have driven, not when and where.  Under one option the government is looking at, fuel duties and the tax disc would be abolished, to be replaced by universal road charges.  If prices are high enough it should encourage drivers not to travel unless they have to - and to avoid busy times.

The result, according to supporters of charging, is the roads will be quieter and those of us prepared to pay will have easier journeys.

Big questions

Ministers are so keen they are even hoping to introduce wider powers to introduce charges for driving in the next session of parliament.  It is quite simply THE big idea for clearing UK jams.  But it is a radical, controversial idea with many unanswered questions. How do you collect the money? How much will we end up paying? And most of all, will it work?

So to answer some of these questions, the BBC decided to set up its own small charging system. We're calling it Pay As You Drive.
 
Motorway driving could be pricey

We have chosen four different drivers in the Midlands, and we have had satellite tracking equipment fitted in their cars.  For a month they will go about their normal motoring lives, but every minute we will keep a record of where they have been.

The prices have been set by Professor Stephen Glaister, the country's top transport economist.  He has used a computer model based on government figures, to work out how much to charge to reflect the delays, accidents and pollution caused by traffic congestion.

15-year countdown

At the end of the month we will send our motorists their Pay As You Drive bill. How much will they spend in a month?  The results could be a surprise to anyone who drives on the UK's jam-packed roads.

Road charging of the sort we are trying out, using GPS satellite tracking, is unlikely to be introduced for at least 15 years.  The technology basically works. But it would require millions of drivers to have tracking units fitted in their cars.

This would probably be made voluntary, with drivers encouraged to join the scheme through financial incentives - ie, lower charges than those levied on drivers without "boxes".

In 15 years' time, automatic numberplate recognition cameras are likely to be in common use on the roads.  They can easily identify drivers who are using their cars without sending back tracking information.

But within five years it is likely a second area of the country, such as Birmingham, will introduce a congestion charge.

Privacy

This would probably use more advanced technology than London and would act as a "pathfinder" road charge for a national scheme.  The real barrier for any government wanting to introduce charges is the political acceptability of road charging.  Drivers will have to be convinced their money will buy easier journeys, that their privacy isn't going to be breached, and above all, that the scheme is fair.

All that is much easier said than done.


Minister to favour road charging 
The new Transport Secretary takes on a daunting department
10 May 2006

New Transport Secretary Douglas Alexander has announced a £10m fund for the development of nationwide road charging schemes.
He hopes new technology will allow drivers to be charged by the mile.

Mr Alexander, promoted in last week's reshuffle, used a speech to outline how he intends to improve UK infrastructure with minimum environmental impact.  His predecessor at the department, Alistair Darling, announced several pilot road charging schemes.

'Time to face facts'

Cambridge, Durham, Bristol, Bath, Greater Manchester, Shrewsbury, Tyne and Wear and the West Midlands were among the authorities developing road charging proposals.

Conservative transport spokesman Chris Grayling said: "Yet again we have a secretary of state whose only solution to our transport problems seems to be a road pricing system which couldn't be introduced for a decade. 

"It's time ministers realised that we need action now to improve transport and not vague ideas for the distant future. They could start by keeping some of the transport promises they've made in the last few years and then quietly dropped."

Lib Dem spokesman Alistair Carmichael meanwhile said the £10m was "simply the first slice of the £18m" promised by Mr Alexander's predecessor in July last year.

Mr Carmichael backed road-user pricing as key to cutting down on congestion and therefore pollution but went on to ask what had happened to a "further £200m a year promised from the Transport Innovation Fund".

"The government has always talked a good game on road-user pricing, but the time has come for them to put their money where their mouth is," he said.

A spokesman from the Chartered Institute of Logistics and Transport welcomed Mr Alexander's commitment to road pricing adding there was "no other long term solution to congestion".

Mr Alexander said road pricing was one of several measures that had been looked at to tackle congestion.

He said that it was time to face "certain basic facts" that as the nation's prosperity improved, people would want to travel more and to travel further.

"And as we travel more, because we live on a crowded island, congestion is set to grow, so if we do nothing we simply face eternal gridlock," he told BBC News.  The debate now was not so much about "why road pricing?", but "how it would be implemented", and the prize for motorists would be "better value out of the road network".

Investment in road capacity would continue where it was justified, Mr Alexander insisted.

Air travel

And he said speed cameras had a role to play, adding: "I've seen it as a driver myself, there is absolutely no doubt where you have cameras, for example where there are tight bends in the road, it makes sense to slow drivers down."

Mr Alexander was in York on Wednesday, where he was opening a new bus service operated by transport giant First.

He also announced the extension of the Oyster smartcard scheme in London, which will see the cards being accepted in the capital's mainline stations.

Earlier, during a BBC Radio 4 Today programme interview, he said that while he did not want to prevent people enjoying the benefits of cheap air travel, he was concerned about the environmental impact.

"This is not simply a domestic problem, this is a challenge we need to meet internationally," he said.

"We believe the right way to address those environmental concerns is to bring aircraft within the emissions trading scheme we are trying to get established at the European Union."