BikeMaps Blog

by Ed Wiebe

The first thing you should know about black ice is that it’s not black.

In fact, black ice is almost completely transparent. It contains no air bubbles or cracks and that makes it look black because we see right through it to the dark road surface that lies beneath. What makes it so treacherous is that surfaces covered in black ice often look wet not icy. If you learn to look out for the common ways it can form you can avoid having your bicycle slip out from under you. Fig. 1. An icy trail early in the morning in Victoria, BC.

The classic black ice scenario is an early morning ride, under clear skies, with an air temperature just above freezing. The paved trail or street looks bare but as you turn a corner you find you’re on thin ice. Your wheels slip sideways and before you know it you’re on the ground nursing a bruised ego or worse.

I live in Victoria, BC, Canada. The winter climate here is warmer than most of Canada, but we see many days when the temperature is close to or below freezing for part of the day. This back and forth cycle of temperature across the freezing point is a key part of the recipe for black ice formation.

Watch out for the following:

• The cold seasons: from when frost starts to form in the fall until the chance of frost diminishes again in spring.

• Clear nighttime or early morning skies — but be wary on a morning when clouds are forming just before sunrise.

• Available water. This may be liquid water or high relative humidity.

• A smooth road or trail surface in a relatively open area, with a good view of the sky.

• A place where the trail or road dips, or a bridge that passes over a shallow valley.

Four ingredients

Black ice needs four basic ingredients. You’ll always find them together, though the path to a slippery surface may vary.

• A reasonably smooth surface.

• Liquid water.

• Freezing temperature at the surface.

• No wind.

In more wintry places than Victoria, you’ll be safer. When the air and ground temperature stay below freezing, there won’t be any liquid water around to freeze into black ice. Watch out for days when snow on or beside roads or paths melts briefly and then refreezes. Also, surfaces treated with road salt can refreeze as they cool further. Fig. 2. https://twitter.com/MDSHA/status/1085672137002835968

Smooth Surface

For black ice to form, a thin layer of water has to be able to cover the small bumps and irregularities in a surface. Asphalt rolled flat on roads and paths is ideal. It’s non-porous and smooth. Concrete can be smooth enough, but surfaces like sidewalks are typically roughened to reduce the risk of slipping.

Water

The water that forms black ice can fall from the sky as rain, or be directly deposited as dew or frost. It may also flow across road or paths when nearby ice and snow melts. Fig. 3. Ice on San Juan Ave in Saanich, BC.

Freezing Temperature

For ice to form on a surface the water that’s present has to be cooled to 0 °C or lower. Strangely, this can happen when the air temperature is warmer than freezing, as long as the surface itself gets cold enough. Often, we’ll encounter black ice on days when the air temperature a few degrees above freezing. Fig. 4. The long wooden trestle over Swan Creek in Saanich, BC, spans a shallow valley and a stream. Cold air pooling in the valley, a source of moisture, and radiative cooling lead to an icy surface.

How does it work?

Let’s go back to the classic scenario mentioned in the introduction. How does the surface chill to freezing if the air temperature is above 0 °C?

Radiative cooling.

The surface of the earth, like every other object in the universe, radiates energy away in the form of infrared light. At night, with no sunlight to warm it, the surface of the earth radiates energy away and cools. If there are clouds in the sky, they slow down the cooling by radiating energy downwards, but on clear nights, the temperature of the earth’s surface can drop sharply.

Fig. 5. Frost forms on surfaces where there is a clear view to the sky. The tree is a source of infrared energy and keeps nearby surfaces a bit warmer.

With a cold surface below it, air that lies near the cold ground at night also cools. When air is cooled its relative humidity increases. This can lead to dew formation and shallow layers of fog (shown below). Cold air is more dense than warmer air so the cold air tends to flow slowly to shallow depressions where it may pool. These layers of air might be only a metre or two thick. They will continue to chill throughout a clear night.

Fig. 6. Radiation fog can form in still air that chills due to radiative cooling. The lawn is a source of moisture.

Wind

If it’s windy the very cold layer at ground level won’t form. The wind will stir up the the layer of air closest to the ground and make it deeper. Wind also encourages evaporation, drying surfaces simply by moving more air past available water.

Dew and Frost

Barring wind, we’ll get a relatively cold surface under clear skies. When a surface cools to the dew point temperature of the air just above it water vapour mixed in with the air will begin to condense. This is dew. If the chilled surface reaches the freezing point the dew will freeze. Since surfaces tend to continue to cool under clear skies overnight a dewy road can become an icy hazard by sunrise.

Fig. 7. Heavy dew on a climb in Saanich, BC, Canada.

When the dew point temperature is below freezing we no longer see dew forming. Instead, water vapour crystallizes directly onto surfaces and grows into tiny separate crystals forming a white crust. This is frost. It’s more visible and rougher so frost is less dangerous to pedestrians and cyclists. Frost is also unlikely to grow on smooth ice that’s already formed. Fig. 8. Frost and some dew drops on grass.

Examples

Galloping Goose Trail southwest of the Selkirk Trestle

This paved trail lies parallel to the Gorge waterway in Victoria, BC (Fig. 1). The water is relatively warm and lies a few metres below the level of trail. The (relative!) warmth of the waterway makes it a prodigious source of water vapour. On a clear night parts of the trail are well exposed to the sky.

Lambrick Park and Nearby San Juan Avenue

Lambrick Park lies in a shallow valley, a broad open area of lawns and playing fields. The colder air that pools there on a still night can be several degrees colder than nearby higher ground. Often, if there’s no breeze, a thin layer of radiation fog forms in the park. There’s a lot of available moisture due to all that lawn. The ground below the fog is probably not below freezing because even fog is a source of energy (everything radiates infrared light), albeit a weak one. Timing is important, though. The surface below may have cooled to below freezing before the fog arrived. Fig. 9. Ice on the trail and frost on grass in Lambrick Park, Saanich, BC.

Some of the streets north of Lambrick Park (Fig. 3) run perpendicularly to the sides of the shallow Shelbourne Valley. Cold, moist air flows downslope in these areas and black ice can form in depressions. Be wary.

Wooden Trestle Bridges

Trestle bridges can be terribly icy (Fig. 4) even though they aren’t particularly smooth. In this case the water, accumulating from rain, melting snow, or condensation, gathers in the porous, ridged surfaces of the planks. Suspended above the ground the entire structure can cool to the air temperature which may be considerably below freezing. Worse still, the bridges are there to help cyclists cross waterways that run below. There is plenty of moisture around.

Summary

Important The key black ice warning sign to remember is clear skies overnight. Clouds in the sky, though cold themselves, add a source of energy for the surface. This means that surfaces under clouds at night tend not to cool below the air temperature.

Wind is also important. Even if only a light breeze, wind can keep relatively warm air moving past the surface. Wind also causes mixing. A thin cold layer can’t form. What cold air that may have otherwise flowed gently downslope toward shallow valleys is not able to pool and get still colder.
Fig. 10. A thermometer that shows when ice is possible.

Extras

Other ways for black ice to form

• Light rain on a cold enough road surface.

• Very cold air temperatures and car exhaust — lots of moisture in exhaust

• Fresh snow, compressed by human activity, that freezes solid when the temperature drops further.

Humidity and Relative Humidity

People often think that clouds are made of water vapour, but this is incorrect. Water vapour is an invisible gas; clouds are made from tiny water droplets or ice crystals that reflect light and so appear white or grey. Humidity is a measure of the water vapour, an invisible gas, that is mixed into the atmosphere. When we say the humidity is high or low we’re referring to how much water vapour is present.

Relative humidity, as you may see reported by a meteorological agency, is a way to talk about the amount of water vapour in air. There is a limit to how much water vapour the atmosphere can hold. That limit depends on the air temperature. Warm air can hold much more water vapour than cold air (there’s an exponential relationship). What’s really important for understanding dew formation or clouds and rain is the relative humidity.

If we measure how much water vapour is present and compare that, as a ratio, with the amount that could be present given the temperature of the air we get the relative humidity. If it’s raining the relative humidity will be close to 100%–that’s why it’s raining! At low relative humidities, below about 25%, we become uncomfortable because our exposed skin and the delicate membranes in our noses and throats dry too quickly.

High humidities are also uncomfortable, even dangerous, especially when it’s warm. This is because we use evaporation to cool ourselves and that’s less efficient when the relative humidity is high.

Dew point Temperature

The dew point temperature is the temperature that a sample of air would have to be cooled to for condensation of water vapour to begin. This doesn’t mean that the all of the air nearby must be chilled. Importantly, any surface in contact with the air that chills to the local dew point temperature will receive condensation.

If the dew point temperature is below freezing it’s called the frost point temperature.

The dew point is always less than the air temperature.

Ed is a Scientific Assistant in the School of Earth and Ocean Sciences at UVic who teaches and works in Climate Modelling and Meteorology. He builds and manages Victoriaweather.ca, a high resolution meteorological network on Vancouver Island.

Thank you for your interest in this position. We are now reviewing resumes.

The BikeMaps.org team is looking for a part time developer to assist with creation of a new webmap for crowdsourcing microscale barriers to walking and rolling. BikeMaps.org was launched in 2014 and is used in over 40 countries for crowdsourcing data on bicycle collisions, near misses, and hazards. Funded by the Public Health Agency of Canada (PHAC), our new tool will be similar in providing people with a mechanism for reporting barriers to safely and comfortably using our city sidewalks and pathways.

The part time developer will assist our lead developer in building the webmap, website, and visualization tools. The ideal candidate will have experience with multiple tools in the list below:

• Front-end web development experience that includes:
  • Familiarity with ReactJS
  • Demonstrated use of Typescript and/or Javascript
  • UI design and experience styling with scss or css
• Experience with Flask, Django or familiarity with Python
• Knowledge of the concepts of REST APIs
• Experience with Git and/or Github or other version control systems
• Familiar with OpenLayers, Leaflet or other JavaScript based mapping APIs
• Experience developing dynamic visualizations and charts
  
  

Competitive wages commensurate with experience. Approximately 10-15 hours per week beginning December 1, 2020. You also must be currently legally permitted to work in Canada.

The BikeMaps.org team is a collegial team of researchers who are community engaged and excited to partner with planners and health professionals. Join our team to help make streets safer and healthier!

Please send your résumé by Monday Nov 9th to:

Karen Laberee
BikeMaps.org Executive Director
klaberee@uvic.ca
250.818.7803

What would appear to many as a perfectly typical driveway was in reality a hotspot for cyclist falls and injuries.

Two cyclists reported falls near the intersection of Willingdon Avenue and Canada Way, in Burnaby, BC, Canada.

In Burnaby, B.C., Canada, near the British Columbia Institute of Technology (BCIT), at least two cyclists fell trying to access the Willingdon Urban Trail (Burnaby’s term for a multi-use path) near the intersection of Willingdon Avenue and Canada Way.

For about fifty metres north of the intersection, the path is replaced by a narrow sidewalk intended only for walking. Instead of dismounting and walking the stretch, many cyclists bypass the sidewalk using an adjacent bus lane and then return to the path using a gas station driveway.

Many cyclists use the bus lane to bypass the 50 m gap in the Willingdon multi-use path.

At least two people have fallen and were injured trying to get back onto the path at this driveway.

Driveways in Burnaby are constructed with an apron lip 4-5 cm above the road. This design standard is from mid-1969—a time when considerations for bicycles were not at the forefront of engineers’ minds.

The 1969 design standard for driveways includes a curb lip raised between 4 - 5 cm above the roadway surface, presenting a solo-bicycle fall hazard to cyclists.

The raised lip, coupled with a cyclist’s shallow angle of approach, conspired to create a fall hazard at this site. As a cyclist gently manoeuvres toward the driveway, their bicycle’s front tire could ricochet against the apron lip, leading to a fall. In the reported cases, the individuals sustained injuries severe enough to require a visit to their GP.

Armed with these incident reports, the Burnaby committee of HUB Cycling (a local cycling advocacy group) contacted the City’s engineering department. When Burnaby engineers evaluated the site and recognised the injury threat, they directed their sidewalk crews to grind down the lip to be flush with the roadway, eliminating the hazard!

The driveway apron lip was ground to be flush with the curb gutter pan, eliminating the fall hazard.

To ensure that all new driveway aprons are safely accessible by bicycle, the Burnaby committee of HUB Cycling is working with staff to update the City’s driveway design standards.

One of BikeMaps.org’s key strengths is the ability to capture incident types not recorded by other reporting systems, including falls and crashes not involving a motor vehicle. In Burnaby and cities around the world, cyclists’ incident reports are helping to make our streets safer for cycling.

by Karen Laberee

How does a workplace encourage so many of its employees to bike to work? If you’re the BC Ministry of Health, it’s helpful to have someone like Eleanor Kallio on staff. Eleanor attended the Pro Walk, Pro Bike conference when it was held in Victoria in September 2004. It was there that she was further inspired to share the benefits of biking to work –increased physical activity and stress reduction, the reduced greenhouse gas emissions and use of fossil fuels, and less congestion on our roadways. Not to mention, it’s often far more enjoyable and convenient than driving! Now she has the practical experience – and demonstrated success - that is a perfect guide for agencies who want to promote bicycling and active transportation for employees. Her recipe for success has three parts: 1) making a plan; 2) working with a great team; and 3) providing inspiration. The results for the Ministry of Health go beyond the benefits of increased bicycling, they also include team building that is beneficial to many aspects of the Ministry of Health’s operations.

Making a plan

The conference gave Eleanor the vision for how Bike to Work Week, held in May each year, could really be “so much more” at the Ministry of Health. She got ideas on how to increase participation and was inspired to make the Ministry a role model for supporting active transportation. Practically, this meant taking on a leadership role and developing a strategy that included a budget, a communication plan, and a schedule for the weeks leading up to the event each year. With the support of the Ministry’s Healthy Workplace Committee and assistance from a co-op student, Eleanor’s plan to grow the Bike to Work Week participation was under way.

Working with a great team

It should be noted that Eleanor was not starting from scratch, and her success can be attributed to working with a great team. There were already Bike to Work Week captains in place at the Ministry of Health and she turned to them for support and additional ideas to grow Bike to Work Week participation. She advertised for additional volunteer captains in areas of the Ministry that did not yet have any in place and she organized a planning meeting to solicit ideas from everyone. In the weeks leading up to Bike to Work Week, she sent regular communications to team captains in order to motivate and keep the energy up. Many of the team captains enthusiastically took on added responsibilities such as organizing a Snack Station and creating Profiles of cycling role models of various staff members.

Providing inspiration

Eleanor and her team’s efforts include a variety of events to inspire and motivate people to join the fun of bicycling to work. They organize a coffee session to share resources and support new riders. Their snack station could be mistaken for a marathon cheering station. Within Bike to Work Week emails shared throughout the agency, they profile various cyclists from across the Ministry to offer inspiration for incorporating bicycling to work into their lives. One of the favourite events that Eleanor has spearheaded over the past three years is a bike raffle. Raffle tickets are sold to win a bike each year and the proceeds go to Kidsport Victoria. Other events have included lunchtime group rides and lunch and learns.

Getting results

Participation in Bike to Work Week at the Ministry of Health has grown considerably since Eleanor’s efforts began started back in 2005. Participants have increased from 92 to 186, and there are now over 20 volunteer captains or supporters and 12 different workplace teams. They’ve expanded their bicycle parking to three times its size and added racks for helmet and lock storage. Biking to Work is not only a way for Ministry of Health employees to lead by example, but it’s become a tremendous team building activity. Having achieved so much enthusiasm for biking to work at the Ministry, Eleanor is now mentoring others to take over the lead in many aspects of the Ministry’s Bike to Work Week activities and events. She is also very keen to see other workplaces adopt some of what she’s learned over the years.

By Verena Engel, MSc. Candidate, Bauhaus-University Weimar

Cycling has many personal benefits: increased health and fitness, reduced stress, time savings, or lower transportation costs are some examples. Beyond that, larger economic and societal benefits can be attained on a municipal or regional scale if the cycling mode share increases. These include lower maintenance and construction costs for urban streets, increased business revenues, reduced health care expenditures, a decrease in traffic congestion, an enhancement of street safety and security, as well as more accessible, livable, and connected communities. That is why investments in bike lanes are desirable for cities all over the world.

Vancouver has started to take advantage of this potential and gained an international reputation as a cycling city. Through an extension of the bicycle network, cycling in Vancouver increased by 3.5 times in just eleven years - from 2% in 2006 to 6.9% in 2017¹. Especially investments in protected bike lanes have proven to be an effective means to increase the cycling mode share in North American cities, Europe, and Australia. Protected bike lanes physically separate cyclists from fast motorized traffic. This increases the actual and perceived road safety for cyclists, along with the level of comfort for a variety of people, and leads to a higher cycling mode share. An evaluation of protected bike lanes in the U.S., for example, revealed that 85% of people that are interested in cycling but have safety concerns, would be more likely to bike if there was a physical barrier between cars and bikes². In Vancouver, 56% of residents want to cycle more³, but almost half of the Vancouver population have safety concerns. Hence, there is a vast potential for more cycling in Vancouver.

In theory, a lot of non-work trips could be done by bike instead of car because they tend to be a lot shorter than commuting trips. Practically, though, most of the current bike trips made in Vancouver are for work or school purposes (see Figure 1). This is not so surprising, considering that most of the protected bicycle infrastructure in Vancouver is targeted towards cycling commuters. It also means that a large potential of more cycling for other purposes is left untouched.

Figure 1 - Mode Share per Trip Purpose in the City of Vancouver, 2017⁴

So what can be done to fulfill this potential? If trips to recreational activities or to run errands should be done by bike, relevant destinations need to be accessible by bike in a safe and comfortable way. This might seem simple, but outside of downtown no businesses and services on commercial high streets can be directly accessed via any sort of bike lane. Some of the commercial high streets are indeed amongst the most dangerous streets to bike on in the City of Vancouver⁵. And still, there are far more people arriving by foot and bike there than on other streets (see Figure 2).

Figure 2 - Mode share comparison between a commercial high street, downtown, and city context⁶

As mentioned earlier, this share could be significantly higher – meaning less cars, less noise, and more safety on our local shopping streets. However, the lack of proper cycling infrastructure is a barrier to cycling for many people: The number of people feeling comfortable cycling on major streets with protected bike lanes is almost 4 times higher than the number of people that feel comfortable biking on major streets without any bike lanes⁷. An implementation of protected bike lanes on commercial high streets could benefit people who currently bike on commercial high streets and would also encourage people with present safety concerns to bike for non-commuting trips. Given that more than 40% of the PM rush hour traffic trips are for non-commuting purpose⁸, this could also reduce traffic congestion on commercial high streets and benefit car drivers.

These are not the only benefits of protected bike lanes on commercial high streets, though. And, of course, there are also some risks that need to be mitigated. A recent study assessed current circumstances that positively and negatively affect an implementation of this type of infrastructure, along with expected opportunities and threats. Some of the most interesting findings are briefly summarized below:

The strengths

There is a high existing demand for protected bike lanes on commercial high streets by current and potential cyclists. Furthermore, commercial high streets are highly suitable locations for bicycle infrastructure. HUB Cycling and the City of Vancouver have identified these streets to be amongst the major gaps in the cycling network due to deficiencies of safety, access to destinations, and the completeness of the bike network. Bike routes on these main streets would be the most logical and direct routes that ease navigation through the city by bike. Lighting, visibility, grade and pavement are mostly better than on residential street bikeways already. Hence, protected bike lanes on commercial high streets could be high quality bike routes in the city.

The weaknesses

The perception of cycling in Vancouver complicates a cycling uptake: A lot of people cannot imagine themselves biking because they don’t know how or think it’s too unsafe. Indeed, cyclists that we see in the city are often from a similar demographic background, look rather sporty and use some kind of special cycling equipment. Many people in Vancouver cannot identify with this image. However, if you take a closer look, you can find people of all ages casually biking off our main streets. Hence, if more people biked on highly visible streets like commercial high streets, this could be changed. Another weakness is that several groups might be under- or misrepresented in the planning and decision-making process. Some business owners in Vancouver, for example, do not agree with how they are publicly represented. These public statements have a high influence on some of the projects, though. If infrastructure should be built with the goal of being suitable for as many people as possible, a more accurate representation of the people who are directly or indirectly concerned has to be ensured.

Figure 3 - 'Typical' cyclist in Vancouver

The opportunities

A negative impact on local businesses is amongst the main arguments against protected bike lanes on commercial high streets. However, a negative effect on businesses was found to be highly unlikely. On the contrary – international and local research has shown that in most cases businesses can expect increased foot traffic and revenues. Bike lanes create a more pleasant public realm that attracts more visitors and presents a competitive advantage against online shopping. Besides, bikes are more space efficient than cars when considering travel lanes and parking space. So, the existing road space can cater to more people if it is dedicated to bikes instead of cars. Moreover, through lower costs, skill requirement, and a higher comfort level, bikes are a more accessible means of transport than cars for many people. Biking can also solve transit challenges like the first-and-last-mile problem, especially when protected bike lanes are provided near transit stations – which are often located on commercial high streets – and in conjunction with a public bike share system. The other way around, transit can promote cycling when distances are longer. This is especially relevant with increasing commute distances and other individual transportation needs. Beyond an increase in local business revenues, citizen mobility and bike-transit synergies, protected bike lanes on commercial high streets have the potential to enhance road safety for all road users and create a higher liveability and more opportunities for social interaction.

The threats

Commercial high streets are amongst the main traffic arteries in the city. While fears of increased traffic congestion generally do not materialize, the limited space that is available can raise design challenges. Safety hazards at conflict zones like intersections or driveways have to be avoided and transit punctuality ensured. However, lots of research is currently being conducted to provide design guidance and solutions for these issues. Another concern is the generally existing fear of change. Along with unsuitable practices of public engagement, such as wrong expectations and a skewed population representation, negative political sentiments can be created. Public participation processes are very important and should be appropriate to ensure that newly built infrastructure suits many people’s needs.

Protected bike lanes are a fairly new phenomenon, which makes some citizens and decision-makers nervous because experiences with them are limited. This is a widespread phenomenon, though, so options for safe and functional design are being explored and discussed in many places. Design guidelines are therefore being developed rapidly and internationally, especially in North American cities like Vancouver. They currently lead the way regarding protected bike lanes and even became role models for European cities with a much stronger cycling culture. Let’s show them how it can be done!

¹McElhanney Consulting Services Ltd., Mustel Group (2018): 2017 Vancouver Panel Survey. Summary Report. City of Vancouver. Available online at https://vancouver.ca/files/cov/2017-transportation- panel-survey-final-draft-20180516.pdf, checked on 9/9/2018.; EPOMM: TEMS - The EPOMM Modal Split Tool. epomm.eu. Available online at http://www.epomm.eu/tems/result_city.phtml?city=274&list=1, checked on 9/10/2018.; City of Vancouver (2018): Walking + Cycling in Vancouver. 2017 Report Card. Vancouver. Available online at https://vancouver.ca/files/cov/cycling-report-card-2017.pdf, checked on 1/10/2019.

²Monsere, Christopher; Dill, Jennifer; McNeil, Nathan; Clifton, Kelly; Foster, Nick; Goddard, Tara et al. (2014): Lessons from the Green Lanes. Evaluating Protected Bike Lanes in the U.S: Portland State University Library.

³City of Vancouver (2018): Walking + Cycling in Vancouver. 2017 Report Card. Vancouver. Available online at https://vancouver.ca/files/cov/cycling-report-card-2017.pdf, checked on 1/10/2019.

⁴McElhanney Consulting Services Ltd., Mustel Group (2018): 2017 Vancouver Panel Survey. Summary Report. City of Vancouver. Available online at https://vancouver.ca/files/cov/2017-transportation- panel-survey-final-draft-20180516.pdf, checked on 9/9/2018.

⁵City of Vancouver (2015): Cycling Safety Study. Final Report. With assistance of Urban Systems, CyclingInCities.

⁶City of Vancouver (2016): Commercial Drive Complete Street. Available online at https://vancouver.ca/files/cov/commercial-drive-complete-street-display-boards-oct2016.pdf, checked on 11/14/2018.; McElhanney Consulting Services Ltd., Mustel Group (2017): 2016 Vancouver Panel Survey. Summary Report. Edited by City of Vancouver. Vancouver. Available online at http://vancouver.ca/files/cov/transportation-panel-survey-2016-final-report.pdf, checked on 5/25/2018.; Stantec (2011): Vancouver Separated Bike Lane Business Impact Study. With assistance of Stantec Consulting Ltd. with Site Economics and Mustel Group Market Research. Edited by Vancouver Economic Development Commission, City of Vancouver, Downtown Vancouver Association, Downtown Vancouver Business Impact Improvement Association, The Vancouver Board of Trade. Vancouver. Available online at http://council.vancouver.ca/20110728/documents/penv3-BusinessImpactStudyReportDowntownSeparatedBicycleLanes-StantecReport.pdf, checked on 5/22/2018.

⁷McElhanney Consulting Services Ltd., Mustel Group (2018): 2017 Vancouver Panel Survey. Summary Report. City of Vancouver. Available online at https://vancouver.ca/files/cov/2017-transportation- panel-survey-final-draft-20180516.pdf, checked on 9/9/2018.

⁸National Complete Streets Coalition: Complete Streets Ease Traffic Woes. Implementing complete streets. With assistance of Smart Growth America, National Complete Streets Coalition. Washington DC.; TransLink (2013): 2011 Metro Vancouver Regional Trip Diary Survey. Analysis Report. Available online at https://www.translink.ca/-/media/Documents/customer_info/translink_listens/customer_surveys/trip_diaries/2011-Metro- Vancouver-Regional-Trip-Diary--Analysis-Report.pdf, checked on 8/6/2018.