Variable Groups 24

The variables or data attributes used by the different BLOS methods can be grouped into several categories such as:

 - Bikeway geometric design (e.g. width, slope)

 - Bikeway environment (e.g. shoulders, proximity to traffic, presence of trees)  - Roadway geometric design (e.g. number of lanes)

 - Bicycle nuisances/hazards (e.g. drain grates, on-street parking, restricted sight distance)  - Bikeway Condition (e.g. pavement condition)

 - Roadway Traffic (e.g. motorized volume/speed)  - Bikeway Traffic (e.g. bicycle volume/speed)  - Intersection specific (e.g. signal delay)  - Built environment (e.g. adjacent land use)  - Network specific (e.g. bicycle network density)

The result of grouping almost 60 variables or attributes into these categories can be seen in Table 2.5. The last column measures the “acceptance” of the variable by indicating how many and what method utilizes the variables. Bikeway design variables are clearly essential; however most methods also include variables associated with motorized traffic volume and speed or motorized traffic facilities geometric design.

Most of the variables can be directly observed or directly measured in the field as the 2010 HCM specify. Most general nuisance/hazards/environment (bikeway or built environment) can be observed in the field whereas most geometric and traffic variables can be measured (speeds) or counted (traffic volumes) in the field. The group of network specific variables is the only exception. For example, some of the network variables such as bicycle network density or average connected node ratio are best measured using software (e.g. a GIS program and using network GIS files).

GIS systems can be useful for implementing BLOS methods by storing the necessary

link/intersection data, implementing BLOS formulas, and mapping the results at the segment, corridor, or urban area level (Lowry and Callister 2012). As mentioned earlier, GIS systems are necessary to effectively implement network or area based methods such as CZA or LTS. Smartphone data can provide detailed route data and some user demographic information. This type of information cannot be incorporated directly into any of the methods that are used to analyze segments or intersections. Smartphone data can be more useful for methods that are used to analyze bicycle networks (e.g. CZA and LTS methods) and for methods that can aggregate users into user groups (e.g. the LTS method).

However, GIS systems do have the limitation of not being routable without large datasets of network parameters indicating the connectivity of links. These sorts of datasets are not

consistently available in all areas. Some options exist for generating routes in order to evaluate some aspect of a bicycle network, including Google Maps and the Tri-Met developed Open Trip Planner7. A combination of GIS and these routable software systems will provide the full

functionality necessary in evaluating BLOS at the intersection, segment, and network levels.

Table 2.6: BLOS Variables by Category

Category Parameter Data Type Methods that Utilize Parameter (see Table 4 for a reference)

Bikeway Geometric

Design

Facility Type Categorical RCI3, BLOS7, BCI9, BISI13, CZA18, BLOS19_{, BLOS}20_, LTS21, BLOS22 Width of Bicycle

Facility

Number (feet) IHS4, BLOS6, BCI9, BSA10, RBCI11, CRC12, BLOS15, BEQI17, BQI18, BLOS19, LTS21 Topographic Grade Number (% grade) RCI3, BSR5,BSA10,

BEQI17, CZA18 Bikeway Environment Width of MV Buffer (proximity to edge of moving traffic lane)

Number (feet) BLOS15, LTS19

Bicycle marking

presence Categorical BSA

10_{, BEQI}17 Presence of bicycle

signage

Categorical BEQI17

Presence of trees Categorical BEQI17 Presence of bicycle

scale lighting Categorical BEQI

17

Width of Shoulder Number (feet) BSS8, BCI9, BSA10, RBCI11, BLOS19, LTS21 Presence of

Sidewalks

Categorical BSA10, BLOS15

Roadway Geometric

Design

Number of Vehicle Lanes

Number (count) BSIR1, RCI3, IHS4, BSR5, BSA10, BSA10, BLOS15, BLOS16, BEQI17, BLOS19, BLOS20, LTS21 Width of Outside

Lane Number (feet) BSIR

1_,BSL2_{, RCI}3_, IHS4, BSR5,BLOS7, BSS8, BCI9, BSA10, RBCI11, BLOS15, BLOS16, BLOS19 Turning Lane Configuration

Categorical BCI9, BSA10, BEQI17 Physical Median Categorical RCI3, BLOS7, BSA10 Frequent Curves Categorical BSA10

Bicycling Nuisance/Hazard

Presence of On- Street Parking

Categorical (2) RCI3, BSR5,BLOS7, BCI9, BSA10, BISI13, BLOS15, BEQI17, BLOS19, LTS21 Occupancy of On- Street Parking Number (%) BCI9, Conflicting Transit

Stop Presence Categorical BLOS

15_, Presence of a Curb Categorical (2) BSA10, BLOS19 Storm Drain Grates Categorical (2) RCI3, BSR5,BSA10, Roadside Hazard Presence (Sand, gravel, vegetation, ditches) Categorical CRC12 Restricted Sight Distance Categorical BSR5, BLOS7, BSA10, BEQI17, Access point density Number (# access points

per mile)

IHS4, RBCI11, CRC12, BLOS16, BEQI17, BLOS20

Numerous

Driveways Categorical BSA

10

Rail Crossings Number (count) RCI3, BSR5, BSA10 Bike Lane Drop Number (# times within

segment)

BQI18, Difficult Transition Number per Segment BQI18,

Bikeway Condition

Pavement Condition Location, Picture, Description

BSIR1_{, RCI}3_{, IHS}4_, BSR5,BLOS7, BSS8, BSA10, CRC12, BLOS16, BEQI17, BLOS19 Roadway Traffic Vehicle Traffic Volume

Number (veh/day) BSIR1,BSL2, RCI3, IHS4, BSR5,BSS8, BCI9_{, BSA}10_{, RBCI}11_, CRC12, BLOS15, BLOS16, BEQI17, BQI18, BLOS19, BLOS22 Right Turning Vehicle Volume

Number (veh per hr or day)

BCI9

Vehicle Speed Number (mph) BSIR1,BSL2, RCI3, IHS4, BSR5,BLOS7, BSS8, BCI9, BSA10, RBCI11, CRC12, BLOS15, BLOS16, BQI18, BLOS19, BLOS20, LTS21 Percentage of Heavy

Vehicles Number (%) IHS

4_,BCI9_{, RBCI}11_, CRC12, BLOS16, BEQI17, BLOS18 Motor Vehicle LOS Categorical (A-F) BLOS7

Bicycle Lane Blockage Categorical LTS 21 Bikeway Traffic Average Speed/Acceleration

Number(ft/s or ft/s^2) BLOS6, BLOS19 Bicycle Volumes Number (bikes/hr or day) BLOS6, BLOS19 Pedestrian Volume

(for multi-use paths) Number (bikes/hr or day) BLOS

6_{, BLOS}19

Intersection Specific

“No Turn on Red” sign

Categorical BEQI17, BLOS22 Intersection Type Categorical BISI13, BLOS22 Intersection Quality Categorical BSA10, CZA18 Crossing Distance Number (feet) BISI13, BLOS22 Number of lanes

crossed for cyclist

left turn

Number of lanes crossed for cyclist right turn

BISI13

Signal Delay Number (seconds) BLOS22

Built Environment

Activity Density Number (Pop. + Employment per sq. mile)

IHS4

Adjacent Land Use Type

Categorical BSR5,BCI9, BSA10, BLOS15, BEQI17, Multi-modal or TOD Proximity Categorical BLOS7 Bicycle parking presence Categorical BEQI17 Network

Connectivity Number (connected node ratio)

BEQI17, CZA18 Presence of Parallel

Facility

Categorical BLOS7

Intersection Density Number (Intersections per sq. mile)

RBCI11 Road Network

Density

Number (Linear Feet per sq. mile)

CZA18 Bicycle Network

Density Number(Linear Feet per sq. mile) CZA 18

Permeability/Barrier Number ("score" per feet-boundary)

BLOS7, CZA18 Stops Number (# stop signs per

mile) BQI

18

Route Simplicity Number (Turns per mile) BQI18 Detour % over shortest path

distance

LTS21

A review of the LOS and stress levels estimation literature indicates that terminology is not consistent and sometimes even confusing. To establish a consistent terminology for this and future project tasks, the following definitions are proposed.