Investigating Carbon Fiber Potential

The proposed pedestrian and bicycle bridge over I-5 at Northgate – linking the North Seattle College on the west with the bus and (future) light rail transit center on the east – has to be pretty high for vehicles on the freeway to pass underneath. That height (about 40 feet above 1st Avenue NE) makes for a looong approach ramp, over 1500 feet, most of it up in the air.

Traditionally these bridge types are steel, and that is what the design codes reference, but SDOT’s team is considering the possibility of using carbon fiber – the stuff that Boeing uses in the 787. Carbon fiber is ten times as strong as steel at less than a quarter of the weight which enables longer spans, smaller foundations, faster construction and less traffic disruption. Andy Bridge, Director of Research and Development for Janicki Industries, says other advantages include reduced visual impacts due to a thinner support structure, easily formed organic shapes, and lower maintenance costs.

The SDOT Northgate Pedestrian and Bicycle Bridge team will be considering many factors – principally safety – in making design decisions, but is excited about the potential of new materials and methods.   This is just one way in which SDOT is seeking to take advantage of innovations in design to reduce costs and provide great service.

Proposed Carbon Fiber Ped and Bike Bridge over I-5 at Northgate

Proposed Carbon Fiber Ped and Bike Bridge over I-5 at Northgate

Quick action protects public and property

As you watch weather reports for the next predicted storm, know that the SDOT Urban Forestry team is looking out for you! Their quick thinking and decision making earlier this month is an example. During the November 6th wind storm that left so many people without power, another impact was waiting to happen: a massive Ash tree along the 1300 block of N 45th Street was swaying with such force that the sidewalk near its base began to crack.

Crews at the adjacent construction project called Urban Forestry for help. They knew who to call since the Urban Forestry team was regularly monitoring the site to ensure surrounding trees were protected during construction.

ConstructionNearTrees

Large Ash trees in the 1300 block of N 45th Street at risk of collapse during November 6, 2014 windstorm

Certified Arborist and SDOT Tree Crew Supervisor Joe Markovich went out immediately to determine next steps. Seeing that the tree could not be saved he called in a contractor he knew could do quality work on short notice. While coordinating on site, Joe noticed that another tree was on the verge of failure, so he expanded the project to cover two tree removals and worked fast to update other agencies responding to the storm.

TreeComesDown

Crews work to remove the unstable trees before they collapse

The threat to public safety warranted a temporary full closure of N 45th Street between Interlaken and Stone Way N, but it wasn’t closed for long. Coordinating with tree removal contractor Kemp West, SDOT Street Maintenance, the Seattle Police Department and King County Metro the risk was abated and the road reopened in less than three hours. The effective communication and collaboration will surely be needed again, as this is the season for Seattle windstorms!

Did you know that right-of-way street trees make city streets safer?

urban treesTrees and landscape in the roadside can have a positive effect on driver behavior and perception, resulting in better safety performance.[1]

A study of Texas urban roads showed a 46% decrease in crash rates across the 10 urban arterial and highway sites after landscape improvements were installed. After the improvements, the number of collisions with trees declined by 71%. Another study found that placing trees and planters in urban arterial roadsides reduced mid-block crashes by 5% to 20%.[2]

All types of roadside treatments—roadside landscaping, median landscaping, and sidewalk widening with tree planting—positively affected vehicle safety outcomes. A marked decrease in the number of pedestrian fatalities was also noted—from 18 to 2 after landscape improvements.[3]

Drivers seeing natural roadside views show lower levels of stress and frustration compared to those viewing all-built settings.[4]

Commuting can be one of the most pervasive stressful experiences of urban life. Stress indicators—such as increased blood pressure—are associated with longer or more difficult commutes. Other affects have also been associated with commuting—lowered job satisfaction, higher illness and absenteeism rates, and lower performance on various cognitive tasks. Incorporating vegetation in roadside landscaping is one way to ease driving stress.

Multiple studies confirm the restorative effects of simply viewing nature in urban settings. [5],[6]

Drivers viewing natural roadsides exhibit lower levels of stress and frustration compared to those viewing built settings. In one lab study, drivers were presented with a stress-causing stimulus and their reactions measured in the course of recovery. Study participants seeing more natural roadside scenes returned to normal baseline measures faster. An “immunization effect” was also detected—the initial exposure to a natural roadside setting decreased the magnitude of stress response to subsequent stressful tasks. Parkway design and roadside vegetation appear to have restorative effects in reducing frustration.

Support for this summary was provided by the national Urban and Community Forestry program of the USDA Forest Service, State and Private Forestry. Green Cities: Good Health summary prepared by Kathleen Wolf, Ph.D., June 29, 2010.

[1] Mok, J.-H., H.C. Landphair, and J.R. Naderi. 2006. Landscape Improvement Impacts on Roadside Safety in Texas. Landscape and Urban Planning 78:263-274

[2] Naderi, J.R. 2003. Landscape Design in the Clear Zone: Effect of Landscape Variables on Pedestrian Health and Driver Safety. Transportation Research Record 1851:119-130.

[3] Mok, J.-H., H.C. Landphair, and J.R. Naderi. 2003. Comparison of Safety Performance of Urban Streets Before and After Landscape Improvements. Proceedings of the 2nd Urban Street Symposium (Anaheim, California). Transportation Research Board, Washington DC.

[4] Wolf, K.L. 2003. Freeway Roadside Management: The Urban Forest Beyond the White Line. Journal of Arboriculture 29, 3:127-136.

[5] Ulrich, R.S., R.F. Simons, B.D. Losito, E. Fiorito, M.A. Miles, and M. Zelson. 1991. Stress Recovery During Exposure to Natural and Urban Environments. Journal of Environmental Psychology 1:201-230.

[6] Kaplan, S. 1995. The Restorative Benefits of Nature: Toward an Integrative Framework. Journal of Environmental Psychology 15:169-182

Join the discussion to improve safety on Rainier Avenue South

RainierPostcard (1)Community meetings scheduled for Nov. 12 and Nov. 18

The Seattle Department of Transportation invites community members to attend one of two community meetings this month to help improve safety on Rainier Avenue South. At the meetings we will review existing conditions and traffic data, discuss potential engineering and enforcement strategies, and hear concerns from residents. SDOT Director Scott Kubly plans to attend both meetings; Mayor Ed Murray will kick-off the Nov. 18 meeting. Nov. 12

6 to 8 p.m.

The Columbia School Cafeteria/Commons

3528 South Ferdinand Street

Nov. 18

4:30 to 6:30 p.m.

The Ethiopian Community Center

8323 Rainier Avenue South

SDOT Director Scott Kubly explained, “We want to have a conversation with the community that uses Rainier Avenue South. Our goal is to improve safety for everyone—whether traveling by car, truck, bus, bike or on foot—while supporting the many businesses along this avenue.”

For more information, please see the webpage for the Rainier Avenue South Road Safety Corridor Project at http://www.seattle.gov/transportation/rainieraves.htm.

 

Can you see it now? Signal Improvement work thanks to Bridging the Gap!

New signal 145thHave you noticed all the work that the Seattle Department of Transportation has been doing recently? Much of that work has been accomplished thanks to the Bridging the Gap (BTG) Transportation initiative. The initiative, currently in its eighth year, has provided key funding for paving roads, constructing new sidewalks, re-striping arterials, rehabilitating bridges, replacing worn out street name signs, striping bikes and sharrows, repairing sidewalks, pruning and planting trees and making improvements along key transit corridors across the city.

While many of the BTG projects are highly visible, funding is also provided for basic maintenance work that is not so visible. Some of the projects include completing preventative maintenance on all 1,070 signals in the city each year and maintaining the “brains” behind the signals. Keeping signals in good working order is important to keeping traffic moving. SDOT has kept its promise to maintain all signals annually and to upgrade and maintain the systems behind those signals.

New traffic signal requests, left turn improvement requests and overall safety concerns are all investigated as part of BTG. If that investigation determines that a new signal or improvement is necessary, funding is available through the BTG program. Over the first seven years of the levy more than 445 new signal requests have been reviewed resulting in 27 new signals installed; 224 left turn requests have been investigated, resulting in 36 improvements; and, more than 333 overall safety concerns have been evaluated resulting in more than 185 improvements. These improvements are not cheap and every request ,whether implemented or not , must go through a lengthy process of on-site monitoring, data analysis, evaluation, review, more number crunching before final approvals.  The actual installation phase entails another equally lengthy process and none of this could happen without the funding from the BTG.

A lot of BTG project work is highly visible and easily recognized; it is the less visible work that helps keep traffic (all modes!) moving and safe. If you would like more information on BTG please visit the website.

 

 

The Speed Hump Report

Data shows that speed humps work.

Data shows that speed humps work.

 

Children are safer when cars move at low speeds  their schools.

Children are safer when cars move at low speeds around schools.

Earlier this year, we told you about SDOT’s plans to install speed humps near schools to encourage more drivers to travel at or below the speed limit. So far this year, SDOT has installed speed humps adjacent to six schools in Seattle: Olympic Hills Elementary, Thurgood Marshall Elementary, Emerson Elementary, Thornton Creek K-8, Eckstein Middle School and Explorer Middle School.

The goal of installing speed humps near schools is to lower vehicle speed where a large number of kids are crossing the street during arrival and dismissal. But do they work? We often hear from people who question whether speed humps, which are only 3 inches high, could possibly change driver behavior. SDOT has increasing evidence showing that speed humps are extremely effective at reducing speed and improving safety. Below are the results of before and after studies SDOT conducted after installing speed humps at three schools in different neighborhoods in Seattle. At all three schools, the percent of drivers exceeding the speed limit decreased more than 70%. Perhaps more impressive, the percent driving more than 10 mph over the speed limit decreased by more than 80%.

speedhumptable

You might be thinking ‘Alright, so they’re effective. Big deal.’ Oh but it is a big deal! Drivers traveling 10 mph or more over the speed limit are some of the biggest threats to kids walking and biking to school. Slowing down allows drivers to stop at a shorter distance which can prevent a crash from happening in the first place. Not only that, vehicle speed itself is a major factor in whether someone walking or biking is killed or injured if hit by a car. A pedestrian hit by a car that’s traveling 35 or 40 miles per hour is likely to be killed, while a pedestrian hit at 20 miles per hour has a 95 percent chance of survival.

survivalspeedhump
With approximately 30 percent of Seattle streets lacking sidewalks, in some neighborhoods kids walking and biking to school have no choice but to share the street with vehicles. One of the great things about speed humps is that they work during school arrival and dismissal and throughout the day. By reducing aggressive speeders on streets where children are walking or biking to school, SDOT is making our streets safer for everyone.

Seawall construction continues with marine mattress and zee panel installation

After installing the first seawall face panels along the waterfront south of Colman Dock, the Elliott Bay Seawall Project is continuing to build infrastructure and habitat enhancements in this area. Recently, marine mattresses, plastic mesh bags filled with stone, were installed along the new seawall panels. These provide a shallow water habitat for migrating salmon and other sea life as they travel along the seawall. Check out the snapshot video of marine mattress installation.

After the marine mattresses were put in place, zee panels were installed – a critical step in building the new seawall. These large, zee-shaped concrete panels provide a counterbalance and support structure for the new overhanging sidewalk. This activity was tidally influenced, so work was completed in the early morning hours while the tide was low.

Zee install 6

Row of installed zee panels south of Colman Dock

Work also continues between Pike and Madison streets, where activities include rip rap removal and steel sheet pile installation.

For more information about seawall construction, visit the Seawall Project website. If you have questions, email the Seawall Project (seawall@waterfrontseattle.org) or call the 24-hour hotline (206.618.8584

Neighborhood Street Fund Large Projects off and running!

S Othello Street AFTERTwelve Neighborhood Street Fund (NSF) large projects were selected for funding in 2013, thanks to the voter-approved Bridging the Gap (BTG) transportation levy. This was the third round of funding provided by BTG and approximately $4.5 million to community-based projects on a three-year cycle, was bolstered by an additional $1 million provided by the Mayor and City Council as part of the savings from the Spokane Street Viaduct Project, bringing the total funding available for this third and final round to $5.5 million. In addition, $2.9 million from the School Zone Camera Enforcement Program will be used to fund four NSF projects near schools. Projects were selected in 2013 will be designed in 2014 and constructed in 2015.

There are 12 projects in the NSF Program all will be completed by the end of 2015. Two projects, the West Duwamish Trail extension and one segment of Pioneer Square ADA improvements, are ahead of schedule and construction will begin in 2014.

Projects to be constructed in 2015:

  • Columbia City Sidewalk Repair:  Construction begins in the first quarter of 2015
  • Georgetown Festival Street:  Construction begins in the second quarter of 2015
  • Pedestrian Improvements (5 locations throughout Seattle):  Construction begins in first quarter of 2015
  • Historic District ADA Improvements: Ongoing through 2015. Some additional work may continue in to 2016 if grant funding is received.
  • Rainier Beach pedestrian improvements:  Construction begins in the fourth quarter of 2015
  • Greenwood Ave N sidewalks:  Construction begins in the second quarter of 2015
  • Rainier Ave S & S Dearborn Street pedestrian improvements: Construction begins in the second quarter of 2015

Each of these projects was submitted by community members to their District Councils for review and selection based on their importance to the community. Projects were then forwarded to the Seattle Department of Transportation (SDOT) for some initial design work and cost estimating.  Each project is then reviewed and evaluated by BTG Oversight Committee members and they then made a recommendation to the Mayor and Council. The full BTG Oversight committee bases their decision on the following factors:  geographic mix, “bang for the buck,” quality of life enhancement, safety considerations and, when appropriate, Pedestrian Master Plan and Bicycle Master Plan criteria.

To learn more about the Neighborhood Street Fund Large Project program and details about the projects selected, please visit their website.

Forecast Calls for Rain and Long Nights – Fall Safety Preparedness

Seattle had one of the nicest summers in recent memory which seemed to last into early October. But after this week’s heavy downpours, windy conditions and pertually gray skies, it’s clear that summer’s over.

Those long summer days are turning into long fall nights and that trend will accelerate in just a little more than a week. The sun will set at 6:05 PM today allowing most of our afternoon peak hour commute to occur with the support of daylight. Seattle, you have one more work week to enjoy these conditions. Daylight savings time ends next Sunday when we ‘fall back’. Starting November 2nd, the sun will start setting before 5 PM.

Our collision data indicates that we have a tough time adjusting to these changing conditions. October is our worst month for crashes in Seattle and November’s not great either. By December we seem to modify our behaviors and collisions drop accordingly despite even longer nights and plenty of that wet stuff that falls from the sky that Seattle is known for.

Serious collisions by month

Serious collisions by month

A 2007 study by professors Paul Fischbeck and David Gerard of Carnegie Mellon University found that pedestrians walking during the evening are nearly three times more likely to be stuck and killed by cars in the weeks after the time change. The study found that it is not the darkness itself that leads to the increase in incidents but the adjustment to earlier nighttime. Pedestrian fatalities decline with each passing month as we adapt to the darker conditions.

With the time change right around the corner and Halloween just a week away (watch for kids!), here are a few tips to help everyone get from Point A to Point B safely:

1. Be visible. Take extra measures to ensure you can be seen when you walk and bike on our streets. Wear light-colored clothing and/or reflective gear so drivers can spot you.

2. Make good decisions when you walk, bike, or drive. Don’t drive distracted (anything from talking on your cell phone to adjusting your costume) and make sure you have a safe way to get home if you plan to party.

3. Take it slow. Give yourself plenty of time to reach your destination. With speed, the frequency and severity of collisions increases.

4. Follow the rules. Drivers should know that every intersection is a legal crosswalk – whether there are pavement markings or not – so drivers should almost always stop for pedestrians. Pedestrians should cross the street at intersections or crosswalks where drivers expect to see you.

5. Always be alert on our streets. A crosswalk is not a suitable location to check your phone and it’s not a good idea to listen to music while bike commuting. Take an active role in safety by keeping your eyes and ears on the road.

 

Future Northgate Connection for Bikes & Peds

Interstate 5 is a critical transportation corridor for Seattle. It helps move people and goods north and south through the center of our city, often at high speeds, unhindered by pedestrians crossing at intersections or bicyclists of various abilities in – or even alongside – the roadway.

Interstate 5 is also an immense obstacle to transportation in the east-west direction wherever the freeway is not lidded or elevated. Where a major arterial does cross, it often has both on- and off-ramps well suited to vehicles, but not particularly friendly for bicyclists or pedestrians.

A new Sound Transit light rail station will soon be built next to the existing King County Metro transit station at 1st Avenue NE and NE 100th Street. The need to connect this transportation hub to the west side of I-5 has become paramount, expressed in planning documents, by public feedback and via support for funding.

Caption:  Artist’s depiction of planned bridge looking west along NE 100th Street

Caption: Artist’s depiction of planned bridge looking west along NE 100th Street

SDOT has responded by planning a new 15-20 wide bridge for bicyclists and pedestrians across I-5 at 100th Street. It would include a ramp on either side to return users to ground level at a less than 5% incline and at least one stairwell on the east side. The bridge would make a direct connection to the mezzanine level of the new light rail station, and would also connect to a new cycle track along 1st Avenue NE.The basic alignment is now being established in consultation with WSDOT, Sound Transit, King County Metro and the North Seattle College (where the landing on the west side will be). The bridge type is also being determined, after which design will begin in earnest.

The planning level estimate for this project is $25M; the City of Seattle and Sound Transit have each agreed to provide $5M towards the cost if the remaining funding is identified by July 2015.

For more information about this project, please visit our project website:

www.seattle.gov/transportation/northgatepedbridge.htm

If you have questions or comments about the project, please contact: Art Brochet, Communications Lead (206) 615-0786 • art.brochet@seattle.gov