Tag Archives: lot size

Essential Ingredients for a Walkable, Compact Town Center

 

By Dom Nozzi

December 20, 2013

I attended a joint citizen board meeting regarding “Sustainable Streets and Centers” in Boulder, Colorado. Here are my thoughts about necessary strategies.

Assumptions

  • Boulder has adopted a clear vision for one or more newly emerging walkable, compact centers in locations such as East Arapahoe Road, Colorado Street, and East Boulder, and intends to use effective tactics to induce the creation and sustainability of such centers.
  • People that desire to live in walkable, compact living arrangements seek a setting that is conducive to such a lifestyle. That setting features low-speed, narrow and human-scaled streets and intersections, very short walking distances to most destinations, buildings pulled up to the sidewalk to create enclosure, and a vibrant experience (in contrast to deadening expanses of parking and large building setbacks). The market for higher density housing will be very weak and unsustainable if such a walkable setting is not provided.
  • 15-minute neighborhoods are an important Boulder objective, which will require the creation of a relatively large number of centers.
  • The objective for centers is a drive to rather than drive through experience, a park-once setting, and a design that makes the pedestrian the design imperative.

General comments

First, strive to use words that resonate and are understandable to non-professional Boulder citizens. Terms such as “multi-way” or “activity center” or “alternate modes” or “corridor” are confusing, uninspiring, and negative. Second, when visioning or seeking comments from citizens, it is important that citizen comments be guided and informed by skilled design professionals (such as Dover-Kohl) who are skilled in presenting information in an understandable, inspiring way (particularly through use of quality graphics). Third, existing housing, employment, or land use patterns should not necessarily dictate visions if such patterns conflict with Boulder objectives. Fourth, the needs or convenience of regional commuters should not trump the low-speed, vibrancy, pedestrian scaled needs of Boulder’s centers.

Toolbox of Strategies that are Essential in Creating a Walkable, Compact Center

(somewhat different toolboxes are needed for other lifestyle zones – “transect zones” – in Boulder)

Land Development Regulations:

  • Motor vehicle parking is behind buildings.
  • Shorter blocks via cross-access pedestrian ways between buildings.
  • Mixed-use zoning to reduce walking/biking distance, and increase 24-hour vibrancy and safety.
  • Relatively high residential densities and commercial intensities.IMG_3045
  • Remove any regulatory barriers to infilling existing parking with buildings.
  • Do not allow gas stations at intersections.
  • Convert parking minimums to parking maximums. Require that the price of parking be unbundled. Increase allowable shared use and leased parking opportunities.
  • Relatively modest building setbacks. At intersections, a sense of place is achieved by requiring buildings to abut the back of sidewalks.
  • Exemption from landscaping requirements.
  • Relatively small minimum lot sizes.
  • Relatively small signs required by the sign ordinance (to help signal a low-speed, pedestrian scaled setting).
  • Proactively overlay a street grid with small block sizes before development is proposed.
  • Do not allow fences to cut off non-street access to adjacent parcels. Fences used should not exceed three or four feet in height along a sidewalk.
  • Emphasize multi-family housing rather than single-family housing in centers and along major streets.
  • Consider requiring at buildings at least two-stories in height for more of a sense of place, a sense of enclosure, mixed use opportunities, and better adaptability to change over time.

Infrastructure

  • Shorter street blocks (200 to 500 feet max).
  • When streets passing through the proposed center are 4 lanes or more in size, they need to be necked down (road dieted) to no more than 3 lanes.
  • Intersections must be kept relatively small in size so that they are pedestrian-scaled. No more than one turn lane in a given direction, relatively narrow travel lanes, and small turning radii.
  • Continuous left turn lanes are to be discouraged. Raised medians with turn pockets are to be encouraged.
  • Raised crosswalks when feasible and appropriate.
  • Street (including lane width) and turning radii dimensions are small and slow-speed.
  • Street lights should be pedestrian-scaled so that light bulbs are no more than 14 feet in height. Taller lights create a highway ambiance and induce higher car speeds.
  • Bus bays are inappropriate in a compact, walkable center due to loss of pedestrian scale and increased pedestrian crossing distance.
  • Sidewalks have straight, rectilinear trajectories rather than curvilinear, suburban trajectories. Curvilinear trajectories, by adding unnecessary distances to walking, are annoying and patronizing to pedestrians. They are mainly benefiting motorists, who obtain a more pleasing view as they drive along a street with curving sidewalks. They also increase the likelihood of dirt cowpaths being formed by pedestrians seeking the shortest route.
  • On-street parking is allowed and priced.
  • Consider visually prominent gateway features at the entrances to centers to clearly signal to motorists that they are entering a low-speed, walkable setting that requires attentiveness.

 

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Filed under Sprawl, Suburbia, Transportation, Urban Design, Walking

A Vision for Designing a Community

 

By Dom Nozzi

April 16, 2006

A Work in Progress

Because it is a matter of fairness and political viability, it is essential that we design for at least three community components: Urban, Suburban and Rural/Preservation.

The following are the examples of components, principles and assumptions for each of the three zones.

The overall objective for the community is equity, quality of life and sustainability.

As an aside, I recognize that the Suburban Zone is not sustainable. It is provided for because America is so overwhelmingly suburban that to not provide for it is politically unsustainable.

Urban

Principles: Sociability, equity, sustainability, supremacy of a quality public realm, compactness, mixed-use, walkability, sense of community, civic pride.

Streets. Low design speed, relatively narrow travel lanes. Maximum size is 2 lanes (major streets have turn pockets.) Roundabouts acceptable. Bulb-outs to increase landscape area, reduce car speeds and pedestrian crossing distance. Turning lanes are either not used or extremely rare. Relatively small dimensions for turning radii, sight triangle. Straight, rectilinear trajectory.Catania Italy walkable

Alleys. Common.

Congestion. Not considered a problem, in part because the Urban Zone is rich in features that allow relatively easy evasion of congestion. Indeed, congestion is seen as an ally to reduce regional air pollution, reduce fuel consumption, reduce car speeds, reduce low-value car trips, promote infill and higher-density residential, promote mixed use, promote compactness, promote trip dispersal.

Congestion fees. Electronic system. Used to recover costs (air pollution, noise, danger, public realm degradation, water pollution, etc.) imposed by motorists entering the Urban Zone. Revenues dedicated to Urban Zone public realm improvements. Revenue, by law, cannot be allocated to road capacity increases.

Signal Light Synchronization. Strongly discouraged, but if employed, timing is based on bus and bicyclist speed (15-20 mph).

Street lights. Structure is no taller than 20 feet — preferably less. Full-spectrum lighting is required.

Lot sizes. Relatively small.

Block size. Relatively small. No more than 200 feet long on a side.

Sidewalks. Required on both sides of street, due to high number of utilitarian and sociability walking trips. Rectilinear and parallel to streets, buildings. Curvilinear alignment not allowed.

Street connectivity. Maximized. High level of trip dispersal in the street network.

Parking.  On-street parking emphasized. Parking is market-priced. Off-street parking, when necessary, is relatively modest and on the side or rear of buildings. Off-street parking is never located at the street corner of a lot at an intersection.

Transit. High frequency and convenient access from residences and shops to stops.

Service vehicles. Fire trucks, delivery trucks and buses are relatively small.

Landscaping. Hardscape much more common than greenscape. Rectilinear rather than curvilinear placement of vegetation.

Street trees. Formally aligned large canopy trees forming street enclosing envelope. Trees are of same species along individual streets.

Land Development Regulations. Form-based (emphasis is on building location and design) rather than use-based. Promoting a quality public realm for pedestrians is the imperative.

Building setbacks. Little or none.

Accessory dwelling units (“granny flats”), home occupations, bed & breakfasts. Expressly allowed.

Drive-throughs, retailers over 30,000 sf of first floor area, parking lots as a primary use. Prohibited.

Maximum building height. 5 stories.

Housing types. Mixed.

Garages. Recessed.

Signs. Relatively small, unlit, subdued.

Building entrance. Faces street.

Land uses. Housing mixed with neighborhood-scaled retail, office, light industrial.

Neighborhood incomes. Mixed

Residential density maximum. No maximum. Market-driven.

Travel choice. Maximized. All forms of travel are provided for.

Schools. Exempt from requirements for outdoor ball fields.

Stormwater management. Relatively low concern for inconvenience flooding means that stormwater basins are relatively small in size. Basins are not placed in front or at the street corner of a lot at an intersection.

Interaction with others. Sociability, connection, interaction.

Public Realm. Aggressive efforts to maximize quality. Regular cleaning.

Suburban

Principles: Separation, privacy, equity, supremacy of private realm, landscaping to simulate nature, large open spaces and large parks, ease of free-flowing travel by car.

Streets. Moderate design speed. Maximum size is 4 lanes. Roundabouts acceptable. Turning lanes are common. Relatively large dimensions for turning radii, sight triangle. Tend to have curvilinear trajectory.huge turn radius for road

Alleys. Rare or non-existent.

Congestion. Considered a serious problem, in part because the Suburban Zone provide very few features that allow evasion of congestion. Congestion fees are therefore important.

Congestion fees. Electronic system. Used to discourage low-value car trips, retain free-flow conditions on at least one lane for emergency access. Revenues dedicated to capacity increases. Signal Light Synchronization. If employed, timing is based on motorist speed (35-45 mph).

Street lights. Structure is 30 feet (or whatever the existing suburban design standard happens to be).

Block size. Variable.

Sidewalks. Optional, due to high percentage of walking trips being recreational. Tend to be curvilinear.

Street connectivity. De-emphasized. Cul-de-sacs common. All neighborhood streets feed into sparse network of major streets.

Parking.  Off-street parking emphasized. Parking is free. Parking can be in front of buildings.

Transit. Low frequency (or no service) and poor access from residences and shops to stops.

Service vehicles. Fire trucks, delivery trucks and buses are relatively large.

Landscaping. Greenscape much more common than hardscape. Curvilinear alignment is most common.

Street trees. Few street trees. Clustered trees of variable sizes and species.

Land Development Regulations. Use-based rather than form-based. Separation of uses and provision for car travel are the imperatives.

Building setbacks. Relatively generous (existing suburban setback requirements).

Accessory dwelling units (“granny flats”), home occupations, bed & breakfasts. Discouraged or prohibited.

Drive-throughs, retailers over 30,000 sf of first floor area, parking lots as a primary use. Allowed.

Maximum building height. 5 stories.

Housing types. Mixed.

Garages. Protruding.

Signs. Relatively large, often lit and animated (due to higher speeds and larger setbacks).

Building entrance. Tend to faces rear parking.

Land uses. Strictly segregated, single-use areas. Areas are either all residential, all commercial, or all industrial.

Neighborhood incomes. Mixed

Residential density maximum. Relatively low maximum (existing suburban setback requirements).

Travel choice. Relatively little. Nearly all forms of travel must be by car.

Schools. Existing conventional standards.

Stormwater management. Relatively high concern for inconvenience flooding means that stormwater basins are relatively large in size. Basins are irregular in shape and incorporate native landscape.

Interaction with others. High levels of privacy, separation.

Public Realm. Relatively unimportant. Emphasis is on generous landscaping, setbacks.

Rural/Preservation

Principles: Extreme levels of separation and privacy, equity, farmlands, environmental preservation, small and compact villages, large open spaces and large parks, ease of free-flowing travel by car.

rural landscape

rural landscape

Streets. ?

Alleys. ?

Congestion. ?

Congestion fees. ?

Signal Light Synchronization. ??

Street lights. ??

Lot sizes. ??

Block size. ??

Sidewalks. Rare. When used, tend to be on only one side of road??

Street connectivity. ??

Parking.  ??

Transit. ??

Service vehicles. ??

Landscaping. ??

Street trees. ??

Land Development Regulations. ??

Building setbacks. ??

Accessory dwelling units (“granny flats”), home occupations, bed & breakfasts. Expressly allowed.

Drive-throughs, retailers over 30,000 sf of first floor area, parking lots as a primary use. Allowed.

Maximum building height. ??

Housing types. Mixed.

Building entrance. ??

Garages. ??

Land uses. Housing mixed with neighborhood-scaled retail, office, light industrial.

Neighborhood incomes. Mixed

Residential density maximum. ??

Travel choice. ??

Schools. ??

Stormwater management. ??

Interaction with others. High levels of privacy, separation.

Public Realm. ??

 

 

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Filed under Sprawl, Suburbia, Transportation, Urban Design