The Moveable Barrier s

Transcription

1 The Moveable Barrier s TIME HAS ARRIVED SYSTEM PROVIDES CONGESTION RELIEF, SAFETY AND SUBSTANTIAL SAVINGS Ewa Bauer had made the trip across the Golden Gate Bridge countless times. Still, January 12 was a special day. Over the weekend workers installed the San Francisco, California, bridge s moveable barriers. As the chief engineer for the Golden Gate Bridge Highway and Transportation District, Bauer s fingerprints were all over the project. The installation had gone better than she could have hoped it had been completed eight hours ahead of schedule but that was a shortterm victory. The real test, the one with lasting impact, would be the bridge crossing. Her anxiety vanished as she started to cross. And it lessened every second of the drive. The barriers were a success. They were a natural fit. She knew it immediately. I could not imagine, as I drove, that those little pylons had ever been used, Bauer said. It seemed like the barriers had always been there. They fit. Other commuters shared similar experiences: They felt the barriers were natural additions and asked, Why didn t we do this earlier? 1

2 MANY USES AND BENEFITS Transportation experts say the Road Zipper System is offi cially coming of age, and the Golden Gate Bridge project is just the most recent example. The uses are growing, too. What started as a tool to make bridges safer has evolved into a traffi c management system to relieve rush-hour congestion. Then there is the newest development: Transportation planners are using the barriers to dramatically reduce the scope of road projects and to save hundreds of millions of dollars. Acceptance and utilisation are increasing, said Martin Leak, a consultant and expert on transportation systems, including the moveable barriers. I think a transformation is under way. There are lots of areas where There are lots of areas where you can t build your way out of problems. The Road Zipper System is a solution often the only solution. MARTIN LEAK, Consultant and Expert on Transportation Systems. you can t build your way out of problems. The Road Zipper System is a solution often the only solution. THE GOLDEN GATE BRIDGE PROJECT Lane management wasn t a new concept for the Golden Gate Bridge. Several times each day workers moved plastic delineators to break the six lanes into a 4-2 confi guration. The delineators did expedite traffi c fl ow but they offered little protection and even less comfort. It was an honour system, where you had to say, I trust that other people will follow this dividing line, Bauer said. While the bridge hadn t seen a fatality in years, there were crashes and they often spilled into other lanes. The only salvation, if there was one, was that fear had led many uncomfortable motorists to lower their speeds as they crossed the bridge. The consensus was that the bridge needed safety improvements. The challenge was how to do it, particularly since the bridge couldn t be widened. Moveable barriers seemed to be out of the question. The Road Zipper System provided by Lindsay Transportation Solutions utilised barriers that took up 18 inches (45.72cm) of lane. Golden Gate lanes were reduced from 12 feet to 10 feet (3.65m to 3.04m) during work completed years earlier. Losing another 9 inches (22.86cm) in each lane was too much for the transportation offi cials. We were very worried about the lane widths, Bauer said. There s a huge difference between a 12-foot-wide lane and a 10-foot-wide lane. Then to take out more. Lindsay began to work with the Golden Gate officials to develop a 12-inch (30.48cm) moveable barrier, which would only take 6 inches (15.24cm) from each lane. The barriers are made of high-density concrete covered with steel jackets. The weight of the concrete keeps the barriers in place, while the reactive tension hingeing system keeps defl ection to a minimum. The barrier in a way is fl exible if it s hit, but the entire length of the barriers holds the section in place, Bauer said. Engineers tested the 12-inch barrier s defl ection basically, how much impact it 2

3 The barriers give the impression that the roadway is wider because you no longer worry about the opposite-direction traffic driving next to you. EWA BAUER, Chief Engineer for the Golden Gate Bridge Highway and Transportation District. can absorb and how far into an adjacent lane a vehicle bounces and U.S. regulators approved the system. The development and approval process had taken years, but the bridge fi nally had what it needed. THE INSTALLATION Planning was thorough and communication to the public frequent. The Golden Gate closed Friday at midnight and the barrier installation began. The installation was perfect, Bauer said. We put a lot of effort into the planning and staging. The work was actually fi nished eight hours early, well in advance of Monday morning s reopening. It was a great accom- plishment, Bauer said. Everyone felt really good about it. But the real test remained. How would the barriers and the narrower lanes work? That was Bauer s biggest worry. The answer came that fi rst morning. The bridge reopened to rave reviews from commuters, who actually felt as if the lanes had been widened. Bauer was one of them, even though she knew space had been lost. The barriers give the impression that the roadway is wider because you no longer worry about the opposite-direction traffi c driving next to you, she said. There is a separation. There is a very strong psychological feeling with the barriers. The Road Zipper machine moves the barriers several times daily and doing so is a simple, quick and safe process, Bauer said. We love this system, she said. 3

4 DESIGNING FLEXIBLY FOR LONG-TERM ACTIVE TRAFFIC MANAGEMENT What s wrong with the way we do it now? Traditionally transportation departments have separated HOV and HOT lanes on one side of the highway through the use of fixed barrier reversible lanes or other methods. This leads to unused capacity and poor space utilisation. FIXED BARRIER REVERSIBLE LANES 4 LANES IN 1 REVERSIBLE HOV/HOT LANE 4 LANES OUT Eight traffic lanes plus a 9th reversible lane. Footprint is 158ft (48.15m) with a 30ft (9.14m) single reversible lane (12ft (3.65m) and two 9ft (2.74m) shoulders for incident management) Two large expanses of unused buffer space, highly uneconomical due to the cost of converting land into highway Flexibility for the future Fixed median with delineators and/or paint lines separate concurrent flow. This does not allow for the use of off-peak space or adjustment to changing traffic patterns A.M. Commute MOVEABLE BARRIER PLACED INSTEAD OF FIXED BARRIER FOR FUTURE FLEXIBILITY 4 LANES IN Adding moveable barriers as fixed static barriers early in a project creates positive separation and allows future flexibility. As conditions change, the machine and other elements can easily be added to make the barriers moveable. The upfront planning minimises the costs, and no demolition or removal of fixed barriers is required. When the initial traffic management approach is no longer optimal, begin using a Road Zipper machine to optimise traffic flow P.M. Commute 4

5 Road Zipper s flexibility in action Same 158ft (48.15m) footprint. 8 lanes in peak period instead of 5, same 4 in the off-peak period. TOTAL of 12 lanes vs 9. If you want it to be 11 vs 9 restripe. Barrier moves anywhere. Incident management is the same as any open highway. No cattle chute to get blocked. Create HOT, HOV or general purpose lanes as needed. Change with overhead signs. FLEXIBLE HOT/HOV LANE IF NEEDED Moveable barriers can manage even narrow lanes, including those of the Golden Gate Bridge, pictured above. The bridge s lanes are only 9 6 (2.89m) when the barriers are in place, yet provide a psychological advantage that actually makes the road seem wider to commuters. The Road Zipper vehicle is protected by the barriers as it works for minutes making the change. 8 LANES IN 4 LANES OUT FLEXIBLE HOT/HOV LANE IF NEEDED 8 LANES OUT How it all works 1. One-metre sections of highly reinforced concrete barriers are linked to form a continuous barrier wall. The barriers have a T top, which acts as a lifting surface for the Road Zipper machine. 2. The machine lifts (but does not drag) the barriers and passes them through a conveyor system. The unique, patented variable-length barriers allow for lane curvature and expansion joints. 3. In one pass, a barrier is transferred up to 24ft (7.31m) and gently set down without damaging the road, at speeds up to 10mph (16km/h)

6 1 2 INTERSTATE 15 If the barriers work well on bridges the Golden Gate Bridge is only one of many examples why can t they help relieve congestion on highways? Caltrans has discovered they can. Offi cials at Caltrans, California s transportation department, looked at congestion relief options for Interstate 15 in San Diego in the late 1980s. At the time many factors came together, including increased use of high-occupancy vehicle lanes and federal funding for Intelligent Transportation Systems. Many governmental agencies, engineers and planners were involved in the I-15 review. All could see the same pattern, and it wasn t particularly surprising: heavy traffi c in one direction and light traffi c in another. A few hours later, the fl ow was just the opposite. Making the observation wasn t particularly diffi cult, nor was the agreement on a broad plan. At that time we looked at more fl exibility, said Edward Cartagena, media information offi cer at Caltrans. But how could Caltrans get that fl exibility? The decision was made to utilise moveable barriers to create a fl exible four-lane highway in the middle of the interstate. Crews placed the fi rst section of barriers in 2008, just as the recession hit and the traffi c slowed. The traffi c demand at that time wasn t as anticipated, Cartagena said. Caltrans held off on making daily adjustments. But the economy and traffi c volumes have now recovered and daily adjustments will begin on I-15 in the next few months. Caltrans is confi dent the system will work on a daily basis. The barriers have shown good results when called on to ease congestion during traffi c accidents and extended holiday weekends. The nearby Coronado Bridge offers more evidence that the daily changes will provide good results. That bridge has a very similar system, and it moves two times daily, Cartagena said. It works well and has been there since the early 90s. ONE LESS LANE IN SPAIN Leak believes the next big step will be implementing the barrier system into road planning and saving millions of dollars in the process. Road planners in Spain are among the early adopters. The targeted 20km (12½ miles) stretch of C-16 between Berga and Bagá is mountainous and curvy. Traffic volume is low during the week, but on winter ski weekends the large number of vehicles can bring it to a standstill. A classic dual carriageway had been planned, but the cost was very high over 3 4 It works well and has been there since the early 90s EDWARD CARTAGENA, Media Information Officer at Caltrans. 6

7 &2. Interstate 15 San Diego, California: The I-15 Express Lanes feature four centre lanes with moveable barriers and direct access ramps for high-frequency BRT service. The managed lanes were developed with the latest technologies that maintain proper flow rates, sense problems, make adjustments at necessary locations and keep travellers informed of their choices. 3&4. Coronado Bridge, San Diego, California: After 18 years of prior service, a new upgraded Road Zipper System was installed on the bridge In The new Reactive Tension barrier is only 18 (45.72cm) wide to give the most space possible to drivers. When impacted, the new barrier has half the deflection of the original, from 52 down to 27 (13.21cm-6.86cm) at NCHRP 350, Test Level The Ben Franklin Bridge, New Jersey: The Road Zipper System balances traffic flow and creates positive protection, which has eliminated cross-over fatalities. 6. For partial width construction, one side of the road can be completely closed for construction while all traffic is diverted to the other side, with a moveable median reconfiguring the roadway in real time to provide more lanes in the peak direction. 7. Interstate 30 Dallas: The Road Zipper System has increased average peak hour main lane speeds by 86%, from 22 to 41mph (35 to 65km/h). 8. The Road Zipper System increases the size of the work zone to create dedicated haul lanes and allow the use of larger equipment. 700 million (US$786 million) for 20km (12½ miles), said Albert Bové Chic, civil engineer in the Civil Works Project Management Department in Barcelona, Spain. It was a hefty price for four lanes that often would see light traffic in both directions. The cost was too high for the government, and we started looking for economical alternatives, Chic said. Planners believed the best idea was to build three total lanes, and make one reversible. During the initial discussion they didn t know about the moveable barriers, so they considered options such as managing the central lane with traffic lights. Yet that didn t solve the biggest problem. There was a lot of concern with road safety, because the existing road is quite curvy and the accident rate is relatively high with many frontal crashes in curves, Chic said. A central managed lane without physical separation between oncoming traffic wouldn t help safety at all. After researching all options the planners became convinced the barriers would solve the safety issue. The cost savings proved astonishing, too. The budget for a third reversible central lane managed with a moveable barrier from Berga to Bagá is about 100 million (US$112.3 million), including all the site work, Chic said, a 600 million (US$673.8 million) saving over the original proposal. THE FUTURE OF EXISTING ROADWAYS Lindsay Transportation officials see their products as ways to provide value to taxpayers when new roads are built and also when trying to make the most of what is already there. Benefits of the Road Zipper System include: Eliminates cross-over accidents and fatalities by providing positive protection from oncoming traffic. Only 10-20% of the cost of adding a new lane. Improves commuter travel times and fuel efficiency. Adapts easily to changing traffic patterns and commuter needs. Operates in all weather conditions. Reusable and easily moves from project to project. Reduces air pollutants. Speeds implementation compared to new construction. Managed lanes can be implemented in all different types of conditions, said Chris Sanders, senior vice president at Lindsay. It s not just bridges or flat surfaces. If you have situations where there are different grade levels, you can still manage the highway through the use of cross-overs and contraflows. There are many solutions to existing congestion issues. As an example Sanders offers Interstate 30 in Dallas, a contraflow road (See graphic on page 4) that crosses a median to borrow a lane of traffic. It s a solution that was created long after the road was built, he said. IMPROVED PLANNING, TOO Factoring moveable barriers into planning for new construction won t always eliminate the need for an entire lane, as was the case in Spain. But the barriers can provide significant flexibility and value when considered from the beginning of a project. Traffic planning is very complicated, Sanders said. You re trying to look years ahead, and it can be difficult to forecast with accuracy. You can t always anticipate a new stadium, or where event traffic will become heavy, or which suburbs will grow and what industries will emerge. 7

8 The key is building in flexibility. A low upfront cost gives you higher flexibility for decades, he said. Road builders who prefer permanent barriers can still have flexibility. You can put down our concrete moveable barriers and let them sit there, just as a permanent barrier would, Sanders said. If you later change your mind, you can add the elements to move the barriers. You won t have to tear out your fixed barriers and other structures. Moveable barriers are just one piece of the Intelligent Transportation System puzzle, Sanders said. Just like ramp metering is turned on and off to adjust traffic flow, we re a piece that gets turned on to add an extra lane, he said. We re an important tool in the managed-lane environment. Existing customers around the world certainly think so. They have chosen to invest in the newest Lindsay systems, Sanders said. It s always a combination of safety and congestion management. Some of the systems are more than 25 years old. They are an integral part of those corridors and they re being reinvested in and maintained. They decided it s worth the money to reinvest in new and improved barriers and machines. FUNDING One challenge facing the moveable barrier systems is operational funding. The moveable barriers are much less costly than new construction, but they do require ongoing operating funds. The budgeting process for operating funds can be very different for transportation departments, which typically build the road and then move onto other projects. Large capital funds can actually be easier to obtain than smaller operating funds. The question of who funds the ongoing operation can be an issue, even though it s much less costly to taxpayers, Sanders said. Taxpayers who know about these systems want these systems. Maybe the public will help make the Saving lives and dollars Officials from the Auckland Harbour Bridge recently upgraded their Road Zipper System, provided by Lindsay Transportation Solutions. There has not been a centre-line head-on collision on the bridge since Lindsay installed the first moveable barrier system at the end of Auckland Harbour Bridge: Injuries from Centre-Line Head-On Collisions Year Fatal Serious Minor The Transit New Zealand Project Evaluation Manual at the time assigned the following costs to head-on motor vehicle accidents: changes happen. Leak, managing director of Auckland, New Zealand-based Resolve Group Ltd., has seen that happen before. He served as a consultant on a number of transportation projects that used the moveable barriers. He was also instrumental in the first moveable barrier project ever, on the Auckland Harbour Bridge in his hometown. The public pushed for the barriers, Leak Fatality $2,946,000 each Serious injury $124,600 each Minor injury $22,000 each These figures equated to an average annual cost saving of $8,720,900 by avoiding the collisions. Using this information, together with the capital, maintenance and operational costs associated with the system, a Benefit Cost Ratio of 8.30 was calculated over an evaluation period of 25 years and a 10% discount rate. Source: Resolve Group Ltd. said. There were crashes and casualties and the public demanded something be done. That was 25 years ago. Since then we ve never had a head-on collision. The public might speak up about spending as it did about safety. That collective voice can lead to change. The public essentially launched these moveable barrier projects, Leak said. 180 River Road, Rio Vista, California U.S.A. Ph: Toll-free: