Street Improvements
Traffic Circulation |
Traffic circulation can have a profound effect on the feeling of pedestrians and even drivers in a community's downtown setting. Conventional roadways can be converted to one direction drives in alternate blocks to allow increased traffic flow without widening existing streets, and thus maintaining the existing pedestrian scale. Definition of overhead space can be done with architectural elements (skyways and arches) or with natural materials like trees. Definition of the overhead plane can help with the perception of a more human scale. Detailing on roadways and in intersections can help define pedestrian zones, and even in some cases act as a passive traffic control device. Green Islands in roadways can help by introducing green into the streetscape and can also contribute to the feeling of a human scale, especially near large roadways Traffic circulation can have a profound effect on the feeling of pedestrians and even drivers in a community's downtown setting. Conventional roadways can be converted to one direction drives in alternate blocks to allow increased traffic flow without widening existing streets, and thus maintaining the existing pedestrian scale. Definition of overhead space can be done with architectural elements (skyways and arches) or with natural materials like trees. Definition of the overhead plane can Traffic circulation can have a profound effect on the feeling of pedestrians and even drivers in a community's downtown setting. Conventional roadways can be converted to one direction drives in alternate blocks to allow increased traffic flow without widening existing streets, and thus maintaining the existing people |
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Streetscape Ryan |
In an urban setting, paving choices become a critical factor in
aesthetics and functional durability. Average daily traffic use,
seasonal variations or temperatures, subsurface geology and traffic speed
all play into the factors of surface amenities. The proper surface type for the focus of the project
has many alternatives. Brick pavers are an expensive option for main
arterial streets, but the durability under the high compression of vehicles
proves to be one of the strongest methods still today. The
environmental factors come in to play however. The frost heave in
Northern Idaho can reign havoc on any surface be it brick pavers, Asphalt,
or concrete. Asphalt is the cheapest alternative to any surfacing project, The materials consist of tar, fine basalt gravel, and a graded subsurface of compacted basalt gravel.. Being the cheapest alternative, asphalt does tend to show more signs of potholes and develops ruts on high traffic areas. |
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A clearly marked
crosswalk in Harvard Square complimented with brick pavers provides a
clearly marked path for pedestrians.
The Northern Idaho
climate can reign havoc on any imperfection in pavement
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Streetscape Elements: Street Amenities |
But tree grates also provide an outlet for rainwater to permeate through, feeding the root system. Signage can be addressed through the illustration on
the left. By combining multiple signs on one post, it alleviates
confusion and sticks with the same theme of the downtown. For any public space, seating must be made available
for persons with disabilities and weary travelers. The styles and
materials are endless, but recommendations do need to be made. For
durability, cast iron, steel, or coated aluminum would be recommended.
For cost feasibility, the list narrows to powder coated aluminum, or
coated steel. The gamut of colors and styles make up for the limited
materials necessary for urban spaces. |
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Multiple-use signage provides space saving techniques
in an orderly form
Benches can either be manufactured or can be
commissioned
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Streetscape Elements: Plant Materials |
With all architectural elements, the goal in mind is to
create a harmonious tie to its surroundings. Street trees are a must to
soften the hardscape and provide shade to areas prone to convection.
Trees provide great benefits to downtown areas. Such benefits
include seasonal shade, shelter, habitat for wildlife, and also help to
absorb carbon emissions from automobiles. Having deciduous trees on a site have positive and negative
aspects. The species of tree found in downtowns is arbitrary, but
certain problems or safety issues need to be considered. Foliage
provided from trees keep the summers cool and the winters warm. They also
provide habitat for squirrels and small birds. Studies have shown that by
placing trees in high traffic areas reduce ambient heat and absorb carbon
dioxide emissions Studies found that the United States absorbs 407 million
to 781 million tons of carbon each year through trees.( www.ancienttrees.org) |
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Trees from the Acer or Maple family provide a clean
shade tree with a high degree of fall color
Quercus or oaks have a larger form, but also have
great fall color. However acorns and sap may cause a messy pavement.
Gleditsia or honey locusts are popular choices for
downtowns. The only problem: they are becoming a standard
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Streetscape Elements: Street layouts |
Street design and layouts for a functional downtown all depend on the size of the populous. In a traditional northwest town, the trend is to have a two-way road with parallel or sixty degree parking at the storefronts. This particular style is apparent and can be seen reflected through most of the west. This design has proven to be successful, but with increasing population and traffic, the roadways become crowded and become difficult to navigate. Where space is available, roads will expand to accommodate the influx of traffic. This poses a problem to designers and the community. Wide roads tend to increase traffic speed, deter pedestrian use, and can sever a community in half. Large intersections increase traffic accidents. Complicated stop lights delay commuting times, stop traffic, and cause noise and air pollution. When this problem occurs, there are only a few limited actions one can take to suture the cut that double or triple lane roads create. |
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Downtowns need to have adequate
Without long term planning, downtowns can become
brownfields like this in Canton Ohio
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Streetscape Elements: Street Layouts Continued |
Pedestrian overpasses provide an elevated retreat from
fast moving cars and trucks, however certain safety precautions need to be
taken into consideration. This added risk of an overpass can be a
costly alternative to getting people from one point to another safely.
Without the proper topography of land, an overpass would need to be
elevated using either building material or moving earth. Such
expenses are costly and inefficient in a downtown setting. Crosswalks were talked about previously in paving
choices. Idaho state lay requires intersections of arterial streets
to have crosswalks that provide ADA accessibility. With expansive
asphalt or concrete roads, the people using the site are more exposed to
faster moving traffic, posing a greater risk of bodily harm.
Solutions to this problem may include slowing down traffic using speed
zones, stoplights, roundabouts or elevating walkways next to storefronts
to protect people from incoming traffic. |
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Pedestrian overpasses are used over high traffic
areas. Chain link fence is used for safety, but is less than
appealing.
Without existing topography, cut and fill can
increase construction cost  Stop lights in multiple lane intersections are cluttered and dangerous for pedestrians |
Streetscape Elements: Paving Continued |
The final surface type covered in this research is
concrete. The highly durable pavement is versatile, but is more
commonly used in highways and interstates rather than rural downtown
settings. With the advent of concrete treatments such as acid
stains, faux finishes and stamping, the flexibility of concrete as a
construction medium can be multi-faceted. |
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Concrete is used for high traffic use because of its
high durability
Settling is more uniform and smoother
Stamped concrete has an appearance of |
Streetscape Elements: Lighting |
Street Lighting is a major amenity to streetscapes.
The style of the lamp poles can add artistic flare and character to the
site. Other characteristics that lighting provides are a sense of
architectural style, safety, locale, way-finding, and artistic use. Architectural style in lampposts, street
lights and bollards can reflect historic or contemporary downtowns by
choosing the proper manufacturer or styles. The details in the
moulds can also reflect regional influences giving a unique identity to
the downtown area. With the ability to mass-produce goods at a cheaper price, the advent of the generic streetlamps spread quickly. Providing a cheap alternative to commissioning designers, the generic lamp provided light for safety without the consideration of energy efficiency, light color spectrum, and aesthetic beauty. The highway light would be a poor choice for a rural downtown setting. Way finding and local style are critical in the design of streetscapes.
The ability to give streets a character make a site easily recognizable
without using signs or markers create good indicators to visitors and
locals entering a downtown. Using a combination of lamp bases,
posts, and lights allow for a truly charming experience without striving
for a certain theme. The final focus area on lighting is the use in artistic content. Light pollution from halogen street lamps can drown out the stars at night. The use of low voltage lights in pedestrian walkways provides a more energy efficient solution to brightly lit corridors in downtowns. With the combination of specific foci, and the use of different textures of plant materials, a dramatic streetscape can punctuate any downtown. Such can be accomplished through implementation of low voltage outdoor lights, or lighted bollards. Street amenities are used to fine tune the atmosphere
of the downtown. The following pages are used to bring to the
surface just some of the basic items that any downtown can have. Bollards were already talked about in lighting, but
will also be covered here. They not only provide light to walkways, but
also serve as openings to public spaces such as plazas, parking lots,
crosswalks and bike or park paths. These serve to alleviate foot
traffic bottlenecks, while safely guarding pedestrians from car traffic. On the subject of guarding, tree guards also function
as protection from car doors, bikes, or auto accidents, protecting the
trees life and monetary value. Not a necessity, but a great insurance for
mature trees. Tree grates also function as protection from another problem called root compaction. Excessive foot traffic can compact the soil so greatly that roots become damaged |
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A generic streetlight common to most downtowns
The style of lighting shown above illustrates a
specific location while keeping to the theme of the neighborhood
Two different lighted bollards act as trail markers
for way finding and provide a safely lit walkway without the light
pollution
Artistic flare adds drama to the textures of night
lighting
Bollards open up thresholds in foot traffic while
keeping out autos
Tree guards provide insurance for expensive street
trees in urban conditions
Tree grates allow water to permeate into the soil for
trees and keep root compaction minimal http://www.ironsmith.com |
Streetscape Elements: Street Layouts Continued |
The latest breakthrough in traffic problem solutions
is the roundabout. Existing all over Europe, roundabouts found their
way into the U.S. in the 1920’s. The original roundabouts were
confusing jumbles of cars and trucks waiting to merge into a loop that
took upwards of ten minutes to get into. Now, after many years of
refining, the roundabout proves to be more efficient at moving traffic at
safer speeds and less waiting than ever before. According to the research findings of Ryerson
Polytechnic Institute under the grant of the United States Department of
Transportation Committee, there was a 39% overall decrease in crashes and
a 90% decrease in fatal injury-producing crashes. The study
also found that traffic delays were reduced by as much as 75%. The
reason for this is that the drivers yield to the right, merging into a
loop. This loop slows traffic down to safer levels, allowing only
minor accidents and minimal pedestrian accidents. |
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Elevated sidewalks add unique interest to downtown
corridors while providing safety
A roundabout in Clearwater Florida
Roundabouts create greenbelts in areas not traditionally found in the western United States.
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Street Design |
"The town center is a safe, attractive, efficient, walkable area with convenient connections to residential neighborhoods and transit facilities." (www.ci.anchorage.ak.us/towncenter, 2002)
Many town centers are located on arterial highways. This means that the design of streets in a town center must caution motorists that the area has a high density of pedestrian traffic. "Both enforcement and design of town center main streets can help to control vehicle speeds for pedestrian safety, which will in turn stimulate more pedestrian activity." (www.franklin.ma. us, 2002)
Town centers are places that people walk to, from nearby neighborhoods. People also drive to the center, park; and then make a number of walking trips to closely located destinations. A small town center may only consist of a church, post office, store and houses. A larger town center could include these, and a block or two of stores and offices. To create streets that warn drivers of a pedestrian area and to create a pleasing town center, some guidelines and elements need to be considered. These will be addressed as: Potential Improvements Streetscape Components Uses and Activities and show Examples of Successful Plazas.
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FIg1: Elegant Streetscape
Fig. 2. Rendering of a streetscape design. Fig. 3 Streetscape in Boston, MA.
Fig. 4 Street paving in Chicago, IL. |
Potential Improvements |
Potential improvements for town center streets: * Curbed sidewalks. * On-street parking. * Well marked and lighted pedestrian crossings. * Off-street parking should be provided off of side streets with good walkway connections. * Use trees, hedges, fences, walls and lighting to define boundaries of the street and give it a cozy scale and atmosphere. * Accommodate pedestrians with landscaping, such as trees for shade and beauty. * Add street furnishings such as benches and trash receptacles for convenience and comfort. * Screen and landscape parking areas and break up large parking areas.
(www.greatroads.com) These simple guidelines will help create an effective town center while taking into consideration parking, pedestrian amenities and the overall aesthetics of the street. In addition to this information there are many components that help make a good streetscape.
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Fig. 5 Sidewalk paving.
Fig. 6 Unique sidewalk paving.
Fig.7 Plant bed.
Fig.8 Bench
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Fig. 9 Planting strip
Fig. 10 Lighting.
Components of a Streetscape |
Streetscape Components:
1. Sidewalk paving -Focus unique paving on the side walk first. -Use to define spaces. -Use paving scale to define pedestrian scale. 2. Tree spaces. 3. Street trees and plant materials. -Planting strips should be 8' or 4-6' in constrained conditions. 4. Street lighting 5. Benches -Two benches per block or one bench per 150' of block face. -Place benches at corners first then at mid block locations. Corners are natural stopping points for pedestrians. -Benches are best placed facing store fronts only when buffered from traffic by on-street parking. -Locate benches in proximity to street trees for shade and enclosure. -Benches need backs. -Place trash containers near but not next to benches. 6. Trash receptacles. 7. Bike racks. 8. Outdoor cafes. 9. Street clocks.
With streetscape components and potential improvements any town can create a successful town center. "Foster walkable, pedestrian-scale town centers that are comfortable and convenient for people to dwell in and travel through without a car." (www.nwf.org/smartgrowth/guidelines.html, 2002) |
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Fig. 12 Street bench.
Fig. 13 Planting strip in Chicago, IL. Fig. 14 Before.
Fig. 15 After.
Fig. 16 Town center |
Fig. 11 Lighting.
Uses and Activities |
Streets have many uses and activities. · Are people using the space or is it empty? · Is it used by people of different ages? · Are people in groups? · How many different types of activities are occurring-people walking, eating, playing baseball, chess, relaxing, reading? · Which parts of the space are used and which are not? · Are there choices of things to do? · Is there a management presence, or can you identify anyone is in charge of the space? (http://www.pps.org)
Sociability · Is this a place where you would choose to meet your friends? Are others meetings friends here or running into them? · Are people in groups? Are they talking with one another? · Do people seem to know each other by face or by name? · Do people bring their friends and relatives to see the place or do they point to one of its features with pride? · Are people smiling? Do people make eye contact with each other? · Do people use the place regularly and by choice? · Do people tend to pick up litter when they see it? (http://www.pps.org) |
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Figure 4: Uses and Activities
Figure 5: Sociability
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The images below were taken in Portland OR Plaza that is also part of an underground parking garage entrance. It provides open space and circulation.
This remnant of the previous building that occupied this urban site reveals the history of the city.
Permanent seating
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