Study Guide Ch. 7 Buildings and Circulation

Question 1

Site Design LARE

Answer 1

Design choices should always be oriented around promoting health, safety, and welfare of site users
As well as minimizing development impacts to the site

Question 2

Establishing the location and orientation of a proposed structure is often the first opportunity that a designer will have to determine a project’s character, as well as the extent of disturbance to a site

Answer 2

Note that commercial uses are especially sensitive to building location given that proximity to customers, ease of access and visibility all directly impact the success of a business

Question 3

Buildings should be located according to the following principles:

Answer 3

- locate buildings on previously disturbed sites if possible. Doing so conserves open space, minimizes construction disturbance and reduces costs, among other things
- locate structures with respect to site topography to minimize grading
- locate structures as close to existing access points as possible to minimize road length. Longer roads increase development costs, result in more impermeable surface and increase overall development impacts while also reducing pedestrian safety.
- locate buildings such that their impact on existing vegetation is limited
- buildings - and especially building entrances - should have a southern orientation, with SSE and SSW being the most ideal, as this promotes solar gain during winter months.
- building entrances should be placed along major pedestrian pathways

Question 4

Scale, massing and character

2-4 stories is human-scale

Answer 4

A building’s scale is determined by its massing and articulation, and buildings should be well-articulated for at least the first two stories to feel in scale with human users.
Human-scaled streetscapes are therefore enclosed by buildings that are two to four stories in height, with any height stories being recessed, or “stepped back”

Question 5

Scale, massing and character

Articulation is good

Answer 5

Long, unbroken expanses of building facades feel imposing and monotonous to pedestrians, and articulation (e.g., large, transparent windows) should be introduced to convey a human scale and create a more inviting streetscape

Question 6

Scale, massing and character

Consider wind and shade

Answer 6

Taller buildings (generally in excess of 10-12 stories) should be designed such that they do not cast shadows or create a wind tunnel effect toward streetscapes and public spaces.
Breaking the building mass up into smaller units can often mitigate the negative impacts caused by tall buildings.

Question 7

Scale, massing and character

Reduce energy use

Answer 7

The energy demands of a building can be lowered by reducing its surface area, building it to a human scale and by increasing the provision of natural light and ventilation inside the structure

Question 8

Scale, massing and character

Footprint = impact

Answer 8

The development impacts of a building can be lowered by reducing the size of its footprint

Question 9

Site circulation

Answer 9

Vehicular, pedestrian, bicycle and multi-user

Placement and extent of site circulation can have a significant impact on the extent of disturbance caused by construction activities. As such, it is critical that any circulation systems be designed to minimize their impact on critical site resources, while also ensuring the health, safety, and welfare of site users.

Question 10

Considerations when designing site circulation

Answer 10

- connectivity
- align entries and exits
- visible entries and exits
- establish a hierarchy
- facilitate wayfinding

Question 11

Connectivity

Answer 11

New site circulation elements absolutely must connect to existing circulation systems serving the site

Question 12

Align entries and exits

Answer 12

Site entry and exit points must be located along the site periphery, and they must be aligned or otherwise coordinated with entry/exit points and intersections found in the surrounding areas

Question 13

Visible entries and exits

Answer 13

Site entry and exit points should be clearly visible and - if multiple entry/exits exist - the designer should establish a hierarchy among these entry/exit points

Question 14

Establish a hierarchy

Answer 14

Site circulation should always have a clear hierarchy.
Whether through scale (e.g., larger streets) or visual character (e.g., high-end material finishes and high level of detailing vs. none), the relative importance of circulation paths should be clear to site users.
Note, however, that all major circulation paths should lead to site entry/exits and key site features

Question 15

Facilitate wayfinding

Answer 15

Wayfinding aids such as signage are one means to help users orient themselves on a site.

Clear sight lines, vantage points/overlooks and site landmarks (e.g., monuments, iconic buildings) also help facilitate wayfinding across a site.

Wayfinding can also be facilitated through breaking the site up into “regions” that use a visual language (including plantings and hardscape selection) to differentiate themselves.

Note that color is often a poor choice for wayfinding signage, given that color does not convey hierarchy and that most people have difficulty distinguishing between shades of the same color. Also note that color-coded signage does not accommodate the needs to sight-impaired and colorblind site users.

Question 16

Exceptions

Answer 16

Hospitals do not follow all of the site circulation principles outlined. Hospital campuses should be divided into public and private/secured zones for the safety of both site users and patients, and patient recreational areas and patient intake should be located inside the private zone. Also note that private, on-campus circulation should be self-contained and not connect to adjacent public roadways.

Question 17

Roadways are organized by the functional classification system, which defines the relative traffic-carrying capacity of a street.
There are four general classifications for roadways, and they are as follows:

Answer 17

Principal Arterial
Minor Arterial
Collector
Local

Question 18

Principal Arterial

Answer 18

Also referred to as major arterials, highways, or controlled-access highways, this class of roadway is designed to carry large amounts of traffic long distances between major urban areas at high speeds.

Note that major arterials typically have controlled access, that is, they can only be accessed by specific connecting roads (typically, highway on-ramps)

Question 19

Minor Arterial

Answer 19

These roadways provide continuous routes through urban areas and most major commercial and institutional uses will be located along minor arterial roadways.
Planning and Urban Design Standards refers to minor arterials as the “backbone” of the urban street network.
Note that residential sites do not typically have direct access to a minor arterial-class roadway.

Question 20

Collector

Answer 20

Collector roads are used to link traffic from local streets to minor arterial roadways.
Note that some residential sites have access to collector roads.

Question 21

Local

Answer 21

The lowest class of roadway, local roads include any street that does not fall into the categories described.
Local roads are typically short (used only to connect to the nearest collector road) and include numerous traffic control devices (e.g., stop signs) to maintain low speed limits.
Note that most residential sites have access to local roads, and that local roads comprise 90% of all streets in the United States, while carrying only 10% of the total traffic volume.

Question 22

Roadway Patterns
Four basic categories

Answer 22

Grid pattern
Radial pattern
“Classic” pattern
Linear system

Question 23

Planning and Urban Design Standards
Classifications of Roadway Patterns

Answer 23

Grid
Grid and Squares
Web
Radial
Curvilinear
Irregular

Question 24

Grid Pattern
Advantages

Answer 24

- Easy to navigate due to simplicity and regularity of their design, as well as their high degree of connectivity
- Provide users with straightforward access to properties, and function best in flat land and in situations where a complex, distributed flow of traffic is preferred
- High levels of connectivity also tend to reduce traffic congestion by distributing traffic across a greater number of streets, rather than concentrating traffic on a small number of arterial or collector streets
- Note that they are also popular with property developers because they provide the most lots per linear foot of street among all roadway patterns

Question 25

Grid Pattern
Disadvantages

Answer 25

- Tend to be visually monotonous, and their straight roads will often encourage higher vehicle speeds
- Moreover, they have no clear hierarchy and - due to their regular pattern - grids are poorly suited to areas with complex topography and critical natural features

Question 26

Radial Pattern
Advantages

Answer 26

Emphasize clear and direct lines to and from a central point

Question 27

Radial Pattern
Disadvantages

Answer 27

Travel that occurs outside the radial lines is typically inconvenient, and radial patterns
- tend to create oddly shaped property boundaries and building sites

Question 28

“Classic” Pattern
Advantages

Answer 28

- Establishes a clear hierarchy of streets that can service multiple points of interest

Due to its flexibility, this pattern works well in areas with topography and important natural features

Question 29

“Classic” Pattern
Disadvantages

Answer 29

Tends to perform poorly in situations where traffic or other interruptions occur along an important arterial roadway.
The classic pattern therefore has multiple critical points of failure due to its relatively low levels of connectivity.

Question 30

Linear System
Advantages

Answer 30

Typically constructed in response to a pre-existing linear element (e.g., railroad, shoreline, canal, highway), linear systems provide convenient flow along one axis

Question 31

Linear Systems
Disadvantages

Answer 31

Do not tend to accommodate travel among other axises, and they have a relatively poor hierarchy

Question 32

Horizontal roadway alignments are composed of two basic geometric components

Answer 32

Straight lines
Arcs

Question 33

Horizontal road alignments

Answer 33

- Road alignment should be as direct as possible, while also addressing topography and other critical natural or cultural features on a site
- all straight lines should be tangent to any arcs (curves) in the roadway (as measured from the roadway’s centerline)
- longer curves in the roadway tend to be safer than tighter curves
- abrupt changes in road character should be avoided if possible (e.g., straight roadway that transitions to a sharp curve or s-curve)

Question 34

Component of a curve

Answer 34

PC: point of curvature (beginning of curve)
PI: point of intersection (point at which the tangents intersect)
PT: point of tangency (the end of the curve)
C: chord (distance between PC and PT)

Question 35

Vertical road alignments

Answer 35

Intersections and site entry/exits should not be placed in locations with steep topography due to sight distance criteria, as well as the danger that steep slopes pose during inclement weather

Question 36

Sight Distance

Answer 36

Length of road ahead of the vehicle that is visible to the driver.
Note that both horizontal (curves) and vertical (hills) changes to the roadway impact sight distance.

Question 37

What are determined by site distance requirements

Answer 37

Roadway alignments
Speed limits
The location of intersections
Site entry/exit points

Question 38

Minimum site distance that exists along any portion of the roadway should allow …

Answer 38

A vehicle (traveling at or below the speed limit) to stop before reaching an object in its path

Question 39

Note that sight distance has a direct impact on general road safety, including protecting pedestrians and cyclists that are sharing or crossing the roadway.

Question 40

In situations where the sight distance is insufficient, what can be used to improve sight distance conditions prior to attempting to re-align the roadway itself

Answer 40

Pruning vegetation
Relocating obstructive elements (e.g., signage)
Eliminating street parking (if it is blocking a driver’s line of sight)

Question 41

Sight Triangle

Answer 41

A site distance located at an intersection

When located at an intersection, the drive must have sufficient sight distance to the intersecting roadways, thereby creating the sight triangle

Question 42

Sight triangle is determined by

Answer 42

Line of sight
Design speed of roadway

Question 43

Note that the sight triangle must be free from any obstructions, including trees and other vegetation. As a general rule, any plants located in the sight triangle should be no higher than 2 ft.

Question 44

Three basic ways in which roads can relate to topography

Answer 44

Parallel to the slope
Perpendicular to the slope
Diagonal across the slope

Question 45

Parallel to the slope
Advantages

Answer 45

Results in easy access between road and buildings

Question 46

Parallel to the slope
Disadvantage

Answer 46

Building orientation disrupts the natural drainage pattern, therefore the proposed grading must direct the stormwater runoff around the buildings

Question 47

Perpendicular to the slope
Advantage

Answer 47

Building orientation is more conducive to the natural drainage pattern

Question 48

Perpendicular to the slope
Disadvantages

Answer 48

Roads will likely be steep given that the steepest slope occurs perpendicular to the contours

Awkward relationship between road and buildings (paths or drives places perpendicular to the direction of the road just be cross-sloped)

Costly grade changes may be required between buildings (e.g., retaining walls)

Question 49

Diagonal across the slope
Advantages

Answer 49

- Efficient storm drainage design
- Good access between the road and adjacent structures
- Gradients less steep than in a perpendicular orientation
- Results in the least amount of disturbance to the landscape

Question 50

Parking lot design issues in section 3 focus on location of lot and any safety issues that might occur from placement of parking and passenger drop-off areas

Answer 50

Note that parking is generally framed as an issue for sites without single-family residential uses

Question 51

When siting a parking areas and passenger drop-off, the following best practices apply:

Answer 51

Minimize disturbance
Make parking convenient
Flat sites
No dead ends
Separate pedestrians and vehicles
Create safe drop-offs

Question 52

Minimize disturbance

Answer 52

Site parking area in location that will not disturb existing site resources, and - if asked to consider drainage patterns - ensure that the parking lot does not drain in wetlands or natural hydrological features

Question 53

Make parking convenient

Answer 53

Locate parking areas near building entrances if possible, and note that most site users will be unwilling to walk more than 700 ft. (1/8 mile) from their parking space to the building entrance
Also note that ADA parking spaces should be nearest to the building entrance.

Question 54

Flat sites

Answer 54

Parking areas should generally be located on a slope of between 1-5%

Question 55

No dead ends

Answer 55

Parking lots should not contain dead ends.
If a dead end is part of the existing conditions, a hammerhead-style turnaround can be added to assist in traffic flows

Question 56

Separate pedestrians and vehicles

Answer 56

Site the parking area such that it minimizes interaction between the main site and traffic/circulation network and pedestrian users

Question 57

Create safe drop-offs

Answer 57

Site drop-offs outside the main traffic flow and located the drop-off area on the passenger’s side of the vehicle

Question 58

Note that business owners often prefer that parking areas are located in highly visible areas for ease of customer access.

Answer 58

Deign best practices generally state that parking areas should be located behind buildings to provide a more engaging and active streetscape.
Most non-residential uses will require access for shipping and receiving activities, and these should be located away from the public parking area.

Question 59

Reducing parking lot size
Options to reduce impervious surface

Answer 59

- pervious material preserves total prkg quantities w/o altering any dimensions
- dimensions of the parking stalls could be reduced preserving total prkg quantities and allowing for portion of lot to be demolished
- dimensions of parking aisles could be reduced
- total parking quantities could be reduced by integrating mass transit into the site

Question 60

When adjusting dimensions of parking areas, the smaller the angle that parking stalls are configured …

Answer 60

The narrower the cross-section of a parking lot will be

45-degree angle stalls would require a narrower drive aisle than a 60- or 90-degree, with the 90-degree stall requiring the largest cross-section.

When accounting for total parking numbers, the 90-degree angle stalls accommodate the most cars per sq. ft. and 45-degree stalls the least

Question 61

Traffic calming highly likely to be on section 3 exam

Question 62

Traffic calming techniques

Answer 62

Speed bump
Raise crosswalk
Speed table
Raised intersection
Neckdowns
Traffic circle
Roundabout
Choker
Realigned intersection
Textured surface
Center island narrowing
Chicane

Woonerf

Question 63

Raised crosswalk

Answer 63

Speed bumps with flat tops marked for pedestrians crossings
Bring the street up to the sidewalk level, increasing pedestrian visibility and safety

Question 64

Speed table

Answer 64

Flat-topped, raised platform that is long enough for both wheels of a car to be on top of the table at the same time

Question 65

Raised intersection

Answer 65

A flat-topped areas that covers the entire intersection
Usually raised to sidewalk level, approximately 6 inches

Question 66

Neckdowns

Answer 66

Curb extensions at intersections used to reduce the roadway and crosswalk width
Also called bulbouts, curb extensions, or intersection narrowings

Question 67

Traffic circle

Answer 67

Raised island located at an intersection around which traffic circulates
Are used on residential streets in lieu of four-way stop signs

Question 68

Roundabouts

Answer 68

Circular raised islands installed at intersections on higher-volume streets such as collectors and arterials are are often used in place of traffic signals or four-way stops. They require yield-at-entry design.

Question 69

Choker

Answer 69

Narrowing devices similar to neckdowns
They are used at mid block to narrow the street and slow drivers

Question 70

Realigned intersection

Answer 70

Used at t-intersections, these realign a straight approach into a curve to slow vehicles

Question 71

Textured surface

Answer 71

Usually used in conjunction with other traffic calming devices, but may be used alone

Question 72

Center island narrowing

Answer 72

Raised islands located at the centerline of a street to narrow road width and slow drivers

Question 73

Chicane

Answer 73

Streets in which curb extensions alternate from one side of the street to the other, thereby creating S-shaped curves.
They reduce both speed and volume, and their design must prevent cut-through driving down the centerline

Question 74

Woonerf

Answer 74

A type of roadway design originally implemented in the Netherlands, in which traffic-calming measures, low speed limits, and shared space between various roadway users are provided to increase safety within the right-of-way

Question 75

Streetscape

Answer 75

The various built elements that comprise a street, including the road, adjacent buildings, street trees, open spaces, sidewalks and site furnishings

Question 76

Discussions related to streetscapes typically involve aesthetic considerations, but streetscape design can impact broader patterns in urban environments

Answer 76

The number and distance of vehicle trips can be reduced not only by mixing land uses and providing mass transit options, but also by creating shorter blocks (between 300-500 ft.) and providing amenities (e.g., site furnishings) that improve neighborhood walkability

Question 77

Five categories that comprise a streetscape

Answer 77

Paving
Planting
Lighting
Furnishings
Public and Private Amenities and Facilities

Question 78

Paving

Answer 78

Considered to be the most visually prominent component of a streetscape, paving materials should be selected based upon local climate conditions and other safety considerations, as well as the overall character of the streetscape in question.

Note that colored paving or changes in materials and texture can be used to design street hierarchy, add visual interest and increase pedestrian safety (e.g., emphasizing the presence of a crosswalk to drivers).
Overly complex paving patterns may disorient users with visual impairments and should be avoided in public areas

Question 79

Planting

Answer 79

Street trees and other plant material provide shade and improve general air quality, while also contributing to the visual character of a street.
They can also provide a physical barrier and visual barrier between the roadway and the sidewalk, thereby increasing pedestrian safety.
Note that street trees should be placed uniformly and should not be located within the sight triangle at intersections.
Distance of tree spacing can be determined by site conditions, but trees should not be spaced closer than their canopy diameter at maturity.
Note also that streetscape plantings require consistent maintenance to avoid safety issues such as low branches that block views to and from the roadway, fallen leaves that clog stormwater inlets, and roots that crack pavement.

Question 80

Lighting

Answer 80

Used to enhance visibility for vehicles, cyclists, and pedestrians, thereby creating a safer streetscape.
Should generally be located between the sidewalk and the roadway, and it can often be located inside planting beds to facilitate pedestrian pavement on hardscape surfaces.
Can also facilitate wayfinding, especially when key buildings, signage, or pathways are emphasized in the lighting design.
Note that lighting - especially streetlights - should also be spaced at uniform intervals, with the one exception being accent lighting used to highlight key site features.

Question 81

Lighting (part 2)

Answer 81

While it may seem intuitive to light the streetscape as brightly as possible to enhance public safety, such a strategy is not necessary, nor may it be particularly desirable to residents whose homes front a brightly lit streetscape.
Outdoor lighting does not need to use high levels of illumination if a clear and consistent lighting scheme is developed.
Light pollution and energy use are always a consideration when designing outdoor lighting, so one would also want to avoid using upward-facing light fixtures (which increase light pollution).

Question 82

Furnishings

Answer 82

Not only provide character to a streetscape, they also perform numerous critical functions.
Benches provide a resting area for pedestrians
Bike racks allow cyclists to store their bicycles in a secure and orderly fashion
Bollards prevent vehicles from entering pedestrian areas
Trash receptacles reduce the frequency of litter.
Note that street furnishings should be located on either side of a sidewalk (i.e., street-side or building-side)
If located toward the street side - and not servicing mass transit or another use located along the roadway - furnishings should be separated from the roadway by a planting area if possible.
Site furnishings should generally never be located in the middle of circulation path, as this would pose a safety hazard to site users.
Note that when selecting seating “L” shaped benches are generally recognized as the seating shape most conducive to encouraging interaction between site users (given that the “L” shape orients users toward one another)

Question 83

Public and Private Amenities and Facilities

Answer 83

Includes public utility boxes and parking meters, as well as various elements (e.g., signage, outdoor dining areas) introduced by private business owners along the streetscape.
As with site furnishings, these elements should be oriented toward either side of a sidewalk and not impede the flow of pedestrians in the streetscape.

Question 84

Building scale

Answer 84

Plays an important role in defining the streetscape due to the sense of enclosure that buildings can provide.

Architecture directly impacts streetscape character. Locating driveways, garages, parking lots, and drive-throughs away from pedestrian areas enhances pedestrian safety and leads to more aesthetically pleasing streetscapes.
And building entrances, windows and other articulation oriented toward the streetscape increase visual interest and improve safety and surveillance.

Question 85

Complete streets

Answer 85

Streets designed and operated to enable safe use and support mobility for all users, regardless of their mode of transportation.
Look to provide safe pedestrian and cyclist infrastructure, encourage the use of mass transit, and they often make use of traffic-calming measures to lower automobile speeds.

Question 86

Pedestrian circulation systems at a site scale should always

Answer 86

- Provide access to and from the site
- Mobility within the site
- Access to any public or recreational spaces on the site

Question 87

Site entries and exits should be

Answer 87

- Highly visible
- Connect to existing circulation networks outside the site

Question 88

Maximum distance most pedestrians are willing to walk to reach their destination

Answer 88

700 ft (1/8 mile)

Most relevant to travel within a discrete site or activity (e.g., walking from a parking space to a restaurant)

Depending upon scale of site, rest areas may be required to make the site accessible to certain site users

Question 89

Pedestrian shed

Answer 89

1/4-1/2 mile

Can be applied to situations that are not as well-delineated (e.g., walking in a city center while shopping at several stores)

Question 90

Note that sidewalks within the public right of way - generally considered to be the backbone of pedestrian circulation systems - are often required by a municipality to be maintained by the adjacent property owners, with many public agencies stipulating that a professional contractor must be hired to conduct any work or maintenance

Question 91

Design criteria that should be applied to the development of a pedestrian circulation system

Answer 91

Separation
Connectivity
Capacity
Accessibility
Amenities

Question 92

Separation

Answer 92

Pedestrian circulation systems should be designed to minimize pedestrian conflicts with vehicles and cyclists, and this is best accomplished by separating pedestrian areas from those used by other forms of transportation.
Pedestrian systems should also provide substantial access to pedestrian-only areas.
When pedestrians and vehicles and/or cyclists intersect, pedestrian areas (e.g., crosswalks) should be clearly identified through signage, pavement changes and other markings

Question 93

Connectivity

Answer 93

In addition to connecting with existing circulation systems both inside and outside the site, pedestrian circulation should follow “desire lines” to important features or locations.
Note that connectivity should not come at the cost of clarity; that is, the designer should minimize interruptions to the pathway system whenever possible.

Question 94

Capacity

Answer 94

Pathway widths should correspond to a hierarchy (i.e., wider paths are more important) and be scaled to accommodate anticipated pedestrian traffic

Question 95

Accessibility

Answer 95

The pedestrian circulation system should service the needs of all users, and disabled users should be given direct access from parking areas to walkways and building entrances.
Accessibility also implies that pedestrian surfaces and pathway gradients are safe to use in all weather conditions, and that rest areas are provided as needed.

Question 96

Amenities

Answer 96

Enhance the usability of the pedestrian circulation system, and they include site furnishings, signage, vegetation, site lighting and special material treatments (e.g., paving) to define points of interest

Question 97

Pedestrians are exposed to the greatest danger when they interact with

Answer 97

Other modes of transportation, particularly automobiles

This occurs most frequently at street crossings

Question 98

Pedestrian safety at intersections can be increased by:

Answer 98

- ensuring that vehicles and roadway users have unobstructed visibility to all crosswalks. Note that unobstructed visibility should be the primary criteria when designing a crosswalk.
- orienting all crosswalks perpendicular to the roadway
- reducing the distance required to cross a street, typically through pedestrian islands or curb extensions known as “bulb-outs” or “Neckdowns”. Note that mid-block crossing locations should make use of “bulb-outs” or pedestrian islands whenever possible, as drivers are less vigilant of pedestrians crossing a roadway when not at an intersection
- lower vehicle speeds
- if designing a new roadway, narrower roads typically enhance pedestrian safety
- visible signage and flashing lights

Note that the CLARB-approved texts generally discourage the use of grade-separated crossings (e.g., pedestrian overpasses or underpasses) because they are often steep and difficult to negotiate for people with physical impairments. In addition, grade-separated crossings are typically expensive to construct.

Question 99

Types of bikeways
Most safe to least safe

Answer 99

1. Bicycle paths
2. Bicycle lanes
3. Wide outside lanes
4. Shared roadways

Question 100

Bicycle paths

Answer 100

Dedicated lanes for bicycle traffic separated from vehicles either by open space or barriers within an existing roadway, or exist as a right-of-way independent from vehicle traffic.
Bike paths are:
- generally 8-12 ft. wide
- a maximum 2% cross-slope, with 1.5% considered ideal
- typically paved with asphalt. Asphalt allows for greater accessibility and is more durable than gravel and concrete is typically more expensive, and concrete joints create disruption in the bike path surface

Question 101

Bicycle lanes

Answer 101

A portion of a larger roadway that is designated for use by bicycles.
Bicycle lanes are delineated by signs, markings, or textured strips within the right-of-way, and they are generally 5-6 ft. wide.
Note that bicycle lanes can be integrated into an existing right of way by:
- narrowing existing vehicular travel lanes
- removing a vehicular travel lane
- removing street parking
- widening the roadway

Question 102

Wide outside lanes

Answer 102

Located on the right side of traffic and are intended to be shared with vehicles in the roadway without impacting traffic flow.
Wide outside lanes are typically ~14 ft. in width because they are designed to accommodate bicycle and vehicle traffic simultaneously

Question 103

Shared roadways

Answer 103

Are the most dangerous form of bikeway
Signage may be used to indicate the presence of a shared roadway, but bicycles are, in essence, treated as automobiles.
This has the potential to impede traffic flow, as any vehicle wishing to pass a bicycle must do so by moving into the left-hand lane.

Question 104

As a general rule, wide outside lane and shared roadway configurations should only be used on low-speed, low-traffic streets.

Answer 104

Streets with higher traffic volumes and speeds should provide dedicated bicycle lanes or bike paths to safely accommodate cyclists.
Note that all bikeways are typically designed to accommodate users traveling up to 20 mph, and all should provide an overhead clearance of at least 10 ft.

Question 105

Regardless of bikeway configuration - whenever bicycles share the roadway with vehicles, they are at risk, and accidents occur most frequently when

Answer 105

- cyclists turn left across oncoming traffic
- cyclists cross an intersection when vehicular traffic is entering from or turning from the right
- either/both bicyclists and motorists fail to yield

Question 106

Criteria to take into account when designing bicycle circulation networks:

Answer 106

- adequate sight lines that provide safety for all users
- topography that is conducive to use by cyclists (8-10% slopes are acceptable over moderate distances, and grades of excess of 10% should be avoided if possible)
- adequate lane widths to accommodate cyclists
- safe conditions at all intersections and other dangerous conditions
- appropriate signage, markings and striping are provided
- adequate drainage infrastructure to prevent water from collecting in the right-of-way
- pavements that meet climate, maintenance and design considerations
- integration with existing bicycle networks

Question 107

Note that bicycle circulation networks tend to be most successful when they are

Answer 107

- safe
- provide direct connections to destinations
- have minimal topography
- allow cyclists to travel uninterrupted, or with a minimum of interruptions (e.g., stop signs at intersections)

Question 108

Rails to trails

Answer 108

Note a that abandoned rail tracks are sometimes re-designed as bike paths (or multi-user trails)
This form of creative reuse takes advantage of the adequate width and gentle slopes that characterize most rail infrastructure and has become an increasingly popular means of providing outdoor recreational opportunities to the public.

Question 109

Multi-user trails designed to

Answer 109

- accommodate a range of users, including walkers/hikers, bicyclists, and inline skaters
- provide opportunities to a broad range of physical fitness levels, and this sometimes means providing alternate routes with more or less challenging features (known as a “graduated difficulty of access”)
- trails within each trail system should be marked with signage that indicates relative difficulty, recognizing that not all trails will be accessible to all users
- users should be given the opportunity to select a trail that matches their goals
Note that the bulk of the multi-used trail system should be designed to be accessible by the broadest cross-section of users as possible
- main trail networks should be paved and designed along gradients of leas than 5% so that they meet ADA requirements
CLARB: primarily used for recreation, with fitness, transportation, and commuting being secondary concerns for the majority of trail users

Question 110

Multi-user trails should be designed such that they:

Answer 110

- are located within open space or linear park areas away from traffic and the built environment
- provide a sense of connection of local ecosystems
- bring users to a variety of destinations
- are connected to a broader circulation network
- minimize interruptions and impediments to travel
- avoid steep slopes
- feel safe for all Trail users and undergo routine maintenance
- provide amenities (e.g., benches, rest areas, interpretive signage) that encourages extended and repeated use

Question 111

Lighting

Answer 111

Note that many multi-user trails will include lighting, even if this lighting is limited to trail entry/exit points and intersections

Question 112

“Nature trails”

Answer 112

Generally designed to different criteria than multi-user trails
Usually surfaces with natural soils or crushed aggregate
Designed to follow the surrounding topography
Grades on nature trails will vary: easy trails 3-5% slopes on average, moderate trails 8-10%, strenuous trails averaging slopes in excess of 10%

Question 113

Conflict on multi-user trails

Answer 113

Although an important public resource, conflicts between various users is a significant concern.
Most accidents occur between cyclists and pedestrians and are caused by unsafe behavior or overcrowding

Question 114

To increase safety for all users,

Answer 114

Trails should be of sufficient width
And/or dividing the trail into well-delineated lanes or “treads” (i.e., surface area) for each type of user

Trails without sufficient width may also separate users under a time-of-use policy that restricts specific uses to certain days or hours

Question 115

Signage

Answer 115

All trails should contain signage that outlines appropriate conduct for each type of user (e.g., cyclists, pedestrians)

Question 116

Note that involving each potential trail user group in the design process is the best way to both understand local needs and resolve the potential for conflict on multi-user trails

Question 117

Universal and barrier-free design principles advocate for site design and site features that allow access to the broadest possible range of people

Answer 117

More accessible a site to a wider range of users, more they are able to benefit from ecological, social, or economic opportunities that it provides

Question 118

Basics

Answer 118

- ADA-accessible parking spaces should be located as close as possible to building entrances, as well as to the shortest accessible path of travel to buildings in general
- all ADA-accessible routes must be continuous and free from obstructions
- all ADA-accessible routes must follow the route planned for the general public to the greatest extent possible
- the primary elements and spaces of a site (i.e., parking, entrances, buildings) must be ADA accessible

Question 119

Key ADA Measurements

Answer 119

- according to the ADA, whenever a walkway exceeds 5% (one foot of elevation change over 20 horizontal feet), is is considered a ramp
- the maximum slope for any ADA-accessible walkway (including ramps) is 8.33% (one foot of elevation change over 12 horizontal feet)
- ADA-accessible walkways without handrails should have a maximum cross slope of 2.1% (1:48) and ramps should have a maximum cross slope of 2% (1:50)

Question 120

Specific Design Considerations

Answer 120

- stairways are the most significant barrier and hazard to site users with disabilities
- any level change (e.g., curbs, stairs) presents a potential safety hazard to a disabled site user
- although ramps are necessary for those in wheelchairs, they are not necessarily easier for other users with physical disabilities. As such, ramps and stairs should be provided together whenever possible.
- handrails are critical to an accessible landscape. Without them, steps, ramps and other grade changes are very difficult to navigate for site users with physical disabilities
- paving materials strongly influence accessibility, especially in regions with rain, snow and ice
- tactile warning strips should be used to delineate edges and along any site furnishings that cannot easily be detected by a guide cane
- bollards should never be placed in the center or main flow of a pedestrian walkway
- chain barriers are especially dangerous to site users and should not be used. To be detected by a guide cane, they need to be located low to the ground, but when located low to the ground they become a trip hazard for all other site users

Question 121

Note that site amenities such as seating, restrooms, shade structures and water fountains make a site easier to negotiate for both disabled and non-disable site users.

Answer 121

Accessible design is best approached as an opportunity to meet the needs of all site users.

Question 122

Elderly Site Users

Answer 122

- elderly site users are generally characterized by diminished perceptual abilities, specifically as this relates to sight and hearing
- elderly site users have particular difficulty seeing small changes in grade. Visual cues should be provided at all grade changes to reduce the risk of tripping and falling accidents among elderly site users.
- comfortable seating will lead to more active and better functioning spaces for elderly site users
- walking is the most common exercise activity for elderly Americans and walking paths can help foster social interaction between the elderly and other populations
- playgrounds and daycare facilities are considered to be complimentary uses for elderly site users because the sight and sound of young people playing is (often) greatly appreciated by the elderly