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B-1Â Â Decision Support Matrix A P P E N D I X B
Bus Lanes Safety Economic Environmental Social Mode Shift Remove bus lanes Low Adverse effect: Conflicts and friction due to the need for buses to pull in and out of traffic or stop in the travel lane. Low Positive effect: Reduced crossing distance for people walking and biking. Medium Adverse effects: Reduced ability to move passengers to and from jobs and businesses; increased bus cycle time may also require additional buses to be added to maintain headways, thus adding to operating costs. Medium Adverse effect: Induces personal vehicle use if it negatively affects transit operations. Medium Adverse effect: Reduces the utility of riding the bus which may promote driving, reduce time spent actively (walking to/from transit), increase interaction with others, and reduce consistent, reliable access for zero- or low-car households. High Adverse effect: Bus reliability and travel times can be significantly slowed by traffic if a bus lane is removed, making transit a less viable and competitive option. In areas where congestion is low, removing a bus lane is likely to have insignificant effects. Narrow bus lanes Low Adverse effect: If the roadway is curved, the lane width is less than 11 ft, or the lane is shared with bicycles. No significant effect. No significant effect. No significant effect. No significant effect Widen bus lanes Low Positive effect: If the roadway is curved, the lane width is less than 11 ft, or the lane is shared with bicycles. No significant effect. No significant effect. No significant effect. No significant effect Add bus lanes Low Positive effect: Removes conflicts and friction from buses pulling in and out of traffic or stopping in the travel lane. Low Adverse effect: Increased crossing distance for people walking and biking. Medium Positive effects: Improved ability to move passengers to and from jobs and businesses; reduced bus cycle time may also require fewer buses to be added to maintain headways, thus reducing operating costs. Medium Positive effect: Reduces personal vehicle use if it positively affects transit operations. Medium Positive effect: Increases the utility of riding the bus which may reduce driving, increase time spent actively (walking to/from transit), increase interaction with others, and improve consistent, reliable access for zero- or low-car households. High Positive effect: Bus reliability and travel times can be significantly improved, making transit a more viable and competitive option. In areas where congestion is low, adding a bus lane is likely to have insignificant effects.
Bicycle Lanes Safety Economic Environmental Social Mode Shift Remove bike lanes High Adverse effects: Removal of exclusive biking space leads to reduced comfort of bicyclists, likely leading to more riding on the sidewalk or in travel lanes, increased conflicts and lack of predictable behavior, and less use and less expectation of bicyclist presence and behavior. The Caltrans Local Roadway Safety Manual cites a 55% CMF for the addition of separated bike lanes and a 65% CMF for painted bike lanes. Medium Adverse effects: Decrease in accessibility affects local businesses and individuals' travel costs and options. Medium Adverse effect: Due to induced driving causing increased emissions. High Adverse effects: Reduced access to physical activity, reduced incentive for local trips affecting community building, and increased direct exposure to emissions. Reduces the ability for some communities (e.g., zero- or low-car households, younger/older populations, disabled populations, and underserved communities) to reach the goods and services they need. High Adverse effect: Unless there is a low- stress, direct alternate route, removing a bike lane is likely to make biking an inviable mode for many, thus decreasing bike mode split. Narrow bike lanes Medium Adverse effect: If reduces width below minimally safe width or reduces the comfort of bicyclists, leading to less use and less expectation of bicyclist presence and behavior; reduced separation from motor vehicles can also lead to decreased visibility of bicyclists. Low/Medium Adverse effects: If the reduction decreases the comfort of bicyclists, the reduction causes a decrease in accessibility that affects local businesses and individuals' travel costs and options. Medium Adverse effects: If the reduction decreases the comfort of bicyclists, causing a decrease in ridership, it induces driving and related emissions. Medium Adverse effect: If the reduction decreases the comfort of bicyclists, causing a decrease in ridership, this reduces physical activity and local trips, affects community building, and reduces the ability for some communities (e.g., zero- or low-car households, younger/older populations, disabled populations, and underserved communities) to reach the goods and services they need. Medium Adverse effect: If the reduction decreases the comfort of bicyclists, this is likely to cause a decrease in ridership.
Safety Economic Environmental Social Mode Shift Widen bike lanes Medium Positive effect: Especially if it increases width above minimally safe width or increases the comfort of bicyclists, leading to greater use and greater expectation of bicyclist presence and behavior; increased separation from motor vehicles can also lead to increased visibility of bicyclists. Low/Medium Positive effects: If the increase improves the comfort of bicyclists, this causes an increase in accessibility that affects local businesses and individuals' travel costs and options. Medium Positive effect: If the increase improves the comfort of bicyclists, thus causing an increase in ridership, this reduces driving and related emissions. Medium Positive effect: If the increase improves the comfort of bicyclists, causing an increase in ridership, this increases physical activity and reduces local trips, affects community building, and increases the ability for some communities (e.g., zero- or low- car households, younger/older populations, disabled populations, and underserved communities) to reach the goods and services they need. Medium Positive effect: If the widening increases the comfort of bicyclists, it is likely to cause an increase in ridership. Add bike lanes High Positive effects: Adding exclusive biking space leads to the increased comfort of bicyclists, which leads to increased use and expectation of bicyclist presence and behavior The Caltrans Local Roadway Safety Manual cites a 55% CMF for the addition of separated bike lanes and a 65% CMF for painted bike lanes. Medium Positive effect: The increase in accessibility affects local businesses and individuals' travel costs and options. Medium Positive effect: Reduced driving leads to reduced emissions. High Positive effects: Increased access to physical activity, increased incentive for local trips, increased community building, and decreased direct exposure to emissions. Increases the ability of some communities (e.g., zero- or low-car households, younger/older populations, disabled populations, and underserved communities) to reach the goods and services they need. High Positive effect: This may increase the viability of biking for transportation, thereby increasing ridership.
Pedestrian Facilities Safety Economic Environmental Social Mode Shift Remove pedestrian facility High Adverse effects: May force people to walk in or along facilities dedicated to and designed for other users; likely also leads to reduced use from pedestrians and less expectation of pedestrian presence. Removes access for those requiring ADA facilities. The Caltrans Local Roadway Safety Manual cites an 80% CRF for the addition of sidewalks. High Adverse effects: A decrease in accessibility affects local businesses and individuals' travel costs and options; removes space that can be used to support area businesses (e.g., sandwich boards, bike parking, and benches). Medium Adverse effect: Reduces the propensity to walk to destinations, inducing driving and related emissions. High Adverse effects: Reduces access and the propensity to walk to destinations, which promotes physical activity, socialization, community building, and propensity for local trips. Also decreases destination accessibility, placemaking, and an inviting atmosphere. Reduces the ability for some communities (e.g., zero- or low-car households, younger/older populations, disabled populations, and underserved communities) to reach needed goods and services. High Adverse effect: Significantly reduces access and the propensity to walk to destinations, thus reducing walking mode split. Narrow pedestrian facility Medium Adverse effect: If it reduces the width below minimally safe width or ADA standard widths. Medium Adverse effects: A decrease in accessibility affects local businesses and individuals' travel costs and options and removes space that can be used to support area businesses (e.g., sandwich boards, bike parking, and benches). Medium Adverse effect: Reduces the propensity to walk to destinations, inducing driving and related emissions. High Adverse effects: Reduces access and the propensity to walk to destinations, which promotes physical activity, socialization, community building, and the propensity for local trips. Also decreases destination accessibility, placemaking, and an inviting atmosphere. Reduces the ability for some communities (e.g., zero- or low-car households, younger/older populations, disabled populations, and underserved communities) to reach needed goods and services. Medium Adverse effect: Reduces the propensity to walk to destinations, thus likely reducing walking mode split.
Safety Economic Environmental Social Mode Shift Widen pedestrian facility Medium Positive effect: If it increases width above minimally safe width or ADA standard widths. Medium Positive effect: Increase in accessibility affects local businesses and individuals' travel costs and options and provides space that can be used to support area businesses (e.g., sandwich boards, bike parking, and benches). Medium Positive effect: Increases the propensity to walk to destinations, thus reducing driving and related emissions. High Positive effects: Increases access and the propensity to walk to destinations, which promotes physical activity, socialization, community building, and the propensity for local trips. Also decreases destination accessibility, placemaking, and an inviting atmosphere. Reduces the ability for some communities (e.g., zero- or low-car households, younger/older populations, disabled populations, and underserved communities) to reach needed goods and services. Medium Positive effect: Increases the propensity to walk to destinations, thus likely increasing the walking mode split. Add pedestrian facility High Positive effects: Added separation from motor vehicle traffic; people do not have to walk in or along facilities dedicated to and designed for other users; likely also leads to increased use from pedestrians and increased expectation of pedestrian presence. Adds access for those requiring ADA facilities. The Caltrans Local Roadway Safety Manual cites an 80% CRF for the addition of sidewalks. High Positive effect: Increase in accessibility impacts local businesses and individuals' travel costs and options; provides space that can be used to support area businesses (sandwich boards, bike parking, benches, etc.). Medium Positive effect: Increased propensity to walk to destinations, reducing driving and related emissions. High Positive effects: Increases access and the propensity to walk to destinations, which promotes physical activity, socialization, community building, and the propensity for local trips. Also decreases destination accessibility, placemaking, and an inviting atmosphere. Reduces the ability for some communities (e.g., zero- or low-car households, younger/older populations, disabled populations, and underserved communities) to reach needed goods and services. High Positive effect: Significantly improves access and the propensity to walk to destinations, thus increasing walking mode split.
Vehicle Travel Lanes Safety Economic Environmental Social Mode Shift Remove travel lanes Near Term: High Positive effects: Even if it contributes to congestion, queueing at slower speeds would reduce the severity of crashes. Shorter crossing distances, reduced crossing exposure for pedestrians, and more feasible clearance intervals for bicyclists. If it results in the addition of a two- way left-turn lane (TWLTL), the HSM provides a 0.71 CMF (SE=0.02) for conversion from a four-lane road (two through lanes in each direction) to a three-lane road with TWLTL (Sec. 13.4.2.3). This may increase the propensity for double parking. Long Term: Medium The compound positive effect of potentially inducing triple divergence in the long term and reducing ADT--the most closely associated factor with crash risk. Near Term: Medium Adverse effects: Reduced automotive capacity, more delay, higher cost of goods movement, and lower mobility. Positive effect: The opportunity for placemaking. Long Term: Low Positive effect: The potential for pass-by trips increased with mode shift from reduced vehicle travel lanes. Near Term: Medium Adverse effects: Local air quality effects related to some stops, stop- and-go traffic, and idling (vehicles occupy smaller areas for longer periods). Long Term: Medium Positive effects: Reduced long-term demand for driving and developments associated with driving (e.g., pavement, smaller parking lots, less runoff, lower emissions). This probably overwhelms the short-term adverse effect in the long run. Short-term adverse effects mitigated with change in fleet characteristics (EVs). Adverse effect: If buses share a travel lane, congestion can decrease reliability and travel times, thereby decreasing the viability of and attractiveness of transit, reducing the likelihood of mode shift to transit. Medium Positive effects: Helps with placemaking because street crossings are shorter and vehicle speeds and volumes are likely lower, thus leading to improved health outcomes over time. This effect is reduced if transit shares the lane and is significantly affected by congestion. High Positive effect: If removing a lane increases motorist travel times, this significantly increases the likelihood of switching to different modes. This effect is reduced if transit shares the lane and is also affected by congestion. Narrow travel lanes Medium Positive effect: Unless existing lane widths were necessary for design vehicles. Can reduce speeds (reduced severity). No significant effect. Medium Positive effects: Slows speeds and reduces emissions. Low Positive effect: Vehicle speeds are likely lower. Low Positive effects: Reduces speeds and travel times, thereby reducing the propensity to drive. Widen travel lanes Medium Adverse effects: Unless existing lane widths were inappropriate for design vehicles. Allows/promotes higher speeds (increased severity). No significant effect. Medium Adverse effect: Increases speeds and emissions. Low Adverse effect: Vehicle speeds are likely higher. Low Adverse effects: Increases speeds and travel times, thereby increasing propensity to drive.
Safety Economic Environmental Social Mode Shift Add travel lanes Near Term: High Adverse effects: Allows/promotes higher speeds (increased severity) and creates longer crossing distances and more challenging clearance intervals for bicyclists. May increase the propensity for double parking. Long Term: Medium Compound adverse effect of potentially inducing more driving in the long term and increasing ADT-- the most closely associated factor with crash risk. Near Term: Medium Positive effects: Increased automotive capacity, lower cost of goods movement and improved mobility. Adverse effect: Less opportunity for placemaking. Long Term: Low Adverse effect: Potential for reduced pass-by trips with induced driving demand (as opposed to other modes). Near Term: Medium Positive effects: Improved local air quality effects related to number of stops, stop-and-go traffic, idling (vehicles occupy smaller area for longer periods of time). Long Term: Medium Adverse effect: Induced demand and developments associated with driving (more pavement, bigger parking lots, more runoff, more emissions). Short-term positive effects mitigated with change in fleet characteristics (EVs). This probably swamps the short-term positive effect in the long run. Adverse effect: If buses share a travel lane, decreased congestion can improve reliability and travel times, increasing attractiveness of transit, reducing the amount of induced demand. Medium Adverse effect: Impacts opportunities for placemaking: street crossings are longer, vehicle speeds and volumes are likely higher, induced demand can increase driving, negatively affecting health outcomes over time. This impact is reduced if transit shares the lane and is significantly affected by congestion. High Adverse effect: If adding a lane decreases motorist travel times, significantly decreases the likelihood of switching to different modes. This impact is reduced if transit shares the lane and is also affected by congestion. One- to Two-Way Conversion Low Positive effects: Converting streets from one-way to two-way can increase safety by slowing speeds, decreasing the risk of a double threat for pedestrians, and creating more pedestrian visibility during left-turns; two-way streets have more conflict points than one-way streets, negating some safety benefits and leading to the "low" benefit rating. High Positive effect: Converting streets from one-way to two-way increase access to and awareness of businesses. Studies show a high effect on business revenue and property values for converted streets. No significant effect. High Positive effect: Slower speeds and improved access often improves neighborhood livability and increases biking and walking traffic. Case studies have indicated a correlation with a decline in crime in areas near converted streets. No significant effect: Likely increases access for people driving but also slows speeds and creates a more friendly environment for people walking and biking.
Safety Economic Environmental Social Mode Shift Remove TWLTL Medium Adverse effect: Removing a two- way left turn lane may increase the frequency of rear-end crashes and reduces the opportunities for pedestrian refuge islands but positively reduces crossing distance if refuge islands did not exist; removing a TWLT may generate a desire for additional motor vehicle lanes to maintain similar traffic; often allows for a four- to three- lane conversion, which can decrease pedestrian exposure and crossing distance; motor vehicle safety benefits are most seen in environments with many access points. Removes opportunities to have a wide center-planted median in areas along a TWLT without access points. Low Decreases motor vehicle access to businesses/services in areas where there are driveways/access points. Low Positive effect: Decreased capacity/motor vehicle access may lead to decreased volumes over time. No significant effect. Low Positive effect: Decreased capacity/motor vehicle access may lead to decreased volumes over time. Add TWLTL Medium Positive effect: Adding a two-way left turn lane may decrease the frequency of rear-end crashes; two- way left turn lanes can provide space for pedestrian refuge islands but adversely creates longer crossing distances if refuge islands are not provided; often allows for a four- to three-lane conversion, which can decrease pedestrian exposure and crossing distance; benefits are most seen in environments with many access points. In areas without access points, a TWLT can be turned into a wide center-planted median. Low Increases motor vehicle access to businesses/services in areas where there are driveways/access points. Low Adverse effects: Increased capacity/motor vehicle access may lead to increased volumes over time. No significant effect. Low Adverse effect: Increased capacity/motor vehicle access may lead to increased volumes over time.
Median Safety Economic Environmental Social Mode Shift Remove median High Adverse effects: Motorized vehicle crash rate increases. Greatly increased potential for head-on collisions Vehicle-vehicle conflict points increased. Veh-ped conflict points increased; eliminates median refuge for crossings. Increases vehicle-bicycle crash frequency at signalized intersections. Increases vehicle-bicycle conflict points. Positive effect: A decrease in speeds, affects all modes. Low Positive effect: This could increase sales for auto-dependent businesses such as gas stations if access is improved. Adverse effect: Could reduce sales receipts if people are less willing to shop as a result of fewer pedestrian crossing opportunities (and perceived safety and comfort along a street). Medium Positive effect: May decrease VMT/emissions due to less direct access to sites with off-site parking. Adverse effect if landscaped median: Stormwater management/drainage effects (increase runoff area). Medium/High Adverse effect: Decreases pedestrian street crossing quality of service. Creates potential barrier(s) in the pedestrian network. No significant effect. Narrow median Low Adverse effect: If the median is reduced to less than 6 feet wide, it cannot serve as a pedestrian refuge. Narrowing the median also generally provides less separation. (HSM Sec. 13.4.2.7) Low Adverse effect: Reduces opportunity for planted median (opportunity for placemaking). No significant effect. No significant effect. No significant effect. Widen median Low Positive effect: If the median is widened to 6 ft or greater, it can serve as a pedestrian refuge. Widening the median also generally provides greater separation and improved safety results. (HSM Sec. 13.4.2.7) Low Positive effect: The wide planted median is an opportunity for placemaking. No significant effect. No significant effect. No significant effect. Add median High Positive effect: Motorized vehicle crash rate decreases. Greatly reduced potential for head-on collisions Vehicle-vehicle conflict points decreased. Veh-ped conflict points decreased; provides median refuge for crossings. Reduces vehicle-bicycle crash frequency at signalized intersections. Decreases vehicle-bicycle conflict points Adverse effect: An increase in speeds, affects all modes. Low Positive effect: Could improve sales receipts if people are more willing to shop as a result of sufficient pedestrian crossing opportunities (and perceived safety and comfort along a street). Adverse effect: Decrease sales for auto-dependent businesses such as gas stations if access is affected. Medium Positive effect if landscaped median: Stormwater management/drainage benefits (reduce runoff area). Adverse effect: May increase VMT/emissions due to less direct access to sites with off-site parking. Medium/High Positive effect: Increases pedestrian street crossing quality of service. Increases continuity of pedestrian network. Improves opportunities for treated midblock crossings. No significant effect.
On-Street Parking Safety Economic Environmental Social Mode Shift Remove parking Low Positive effect: Decreased conflicts from parking maneuvers; reduced access to parking may decrease driving demand/VMT, thereby reducing crashes Adverse effect: All else is equal, increased likelihood of double parking (hazardous behavior); street parking can act as traffic calming. Medium Adverse effect: Decreased meter revenue, may make customer access (finding parking) more difficult for businesses without off-street parking and may remove space for loading/unloading delivery vehicles. Medium Near Term: Adverse effect: Increased circling for parking and associated emissionsâprovided all else equal, and that street parking constitutes a meaningful share of area parking. Long Term: Positive effect: Decreased parking access can reduce demand for driving over time, reducing VMT/emissions. Low Adverse effect: All else equal, increases the amount of time spent circling for parking, with decreased utility for motorists. High Positive effect: Decreasing parking supply can increase barriers to driving, and increases the likelihood of switching to different modes. Narrow parking Low Positive effect: Reduce pedestrian crossing exposure Adverse effect: If bicycle facilities are adjacent, it may increase the likelihood of "dooring"; may increase conflicts between people entering/exiting their vehicles and moving motor vehicles. No significant effect unless narrowing affects the ability to use parking as loading zones, in which case there would be a medium negative effect. No significant effect. No significant effect. No significant effect. Widen parking Low Adverse effect: Increase pedestrian crossing exposure Positive effect: If bicycle facilities are adjacent, it may decrease the likelihood of "dooring"; may decrease conflicts between people entering/exiting their vehicles and moving motor vehicles. No significant effect unless widening allows parking to be used as a loading zone, in which case there would be a medium positive effect. No significant effect. No significant effect. No significant effect. Add parking Low Adverse effect: Increased conflicts from parking maneuvers; increased access to parking may increase driving demand/VMT, thereby increasing crashes. Potential sight distance issues for driveways or intersections. Positive effect: All else is equal, decreased likelihood of double parking (hazardous behavior); street parking can act as traffic calming and serves as a buffer to sidewalks and some bicycle facilities. Medium Positive effect: Increased access to commercial uses, if managed appropriately, ability to serve for loading/unloading delivery vehicles, and may improve customer access (finding parking) for businesses without off-street parking. Medium Positive effect: Decreased circling for parking and associated emissionsâprovided all else equal, and that street parking constitutes a meaningful share of area parking. Long Term: Adverse effect: Increased parking access can induce demand for driving over time, increasing VMT/emissions. Low Positive effect: All else equal, decreases the amount of time spent circling for parking, with increased utility for motorists. High Adverse effect: Increasing the parking supply can decrease barriers to driving, increasing the propensity for driving.
