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Home My WebLink AboutExhibit 9APPENDIX B SILVER BLUFF AREA TRAFFIC CALMING STUDY PUBLIC INVOLVEMENT -1 City of Miami 11,11416 Traffic Calming Study The Silver Bluff Neighborhood What is Traffic Calming Types of Measures Alternatives Effectiveness of Measures Process The Neighborhood Functional Classification Traffic Data Collection Existing Problems Preliminary Alternatives 2 `Physical retrofit of traffic operations and management strategies on existing streets, designed to reduce adverse traffic impact such as speeding and excessive volumes and to nprove safety and amenity." 3 • tiv!,?' Passive Control Measures Least restrictive Do not physically prevent an action Easily violated by drivers Active Control Measure Most restrictive Physically prevent an action Create visual impression that streets are not only for motorists 4 Ve tica Defiectio Measures • Speed Humps/Tables • Raised Crosswalks • Raised Intersections. • Speed Cushions • Full & Partial Closures • Diverters • Median Barriers • Forced Turn Islands • Roundabouts • Curb Extensions • Mini Roundabouts • Neckdowns • Chicanes - Chokers • Alternate Side Parking • Slow. Points • Realigned lntersection • Gateways • Center Island Medians • Ped Refuge islands 5 0_44 t6* "7- K. . . On -Street Parking • Bicycle Lanes • Narrowed Lanes ▪ Streetscaping • Speed. Gun w1VMS • Special: Signs • Forced Perspective • Rumble Strips • Rumble Stripes Color: Pavement •.Textured Pavement • Textured .Markings 3 VOLUME CONTROL MEASURES Street Closures (Full / Partial) Semi-Diverters at intersections Diagonal Diverters Median Barriers Forced Turn Channelization Restrictive one-way street patterns Right -in Right -out Diverters 6 es 114.- mr„ SPEED CONTROL MEASURES Speed Humps and Speed Tables Traffic Circles and Roundabouts Mid -Block Medians Chicanes Narrowings at Mid -block and Intersection (choker/Neckdowns) Brick Pavers Central Island Narrowing Horizontal Alignment Changes Landscaping advantages: estricts all through raffic elf enforcing Disadvantages: May redirect traffic to other local streets May increase trip length for some drivers May increase emergency response times 7 VOLUMECONTROL MEASURES Pal- . JtR. CA - ._.�.4 CoralGb�_p Advantages Reduces cut -through traffic Restricts movements while Maintaining access for esidents Self -enforcing and aesthetically pleasing Reduces crossing distance for pedestrians Emergency vehicles can travel in the restricted direction Disadvantages Diverts traffic to parallel streets. Increases trip length for some residents Restrict curbside parking adjacent to the device increases emergency response time Maintenance responsibility oe x. AZ 8 VOLUME CONTROL MEASURES Advantages: • Effective in reducing the speed • Reduces accident potential severity • ,Reduces conflict points • Provides orderly and continuous flow of traffic flows • Aesthetically landscaping Disadvantages • May be restrictive for some large emergency and service vehicles • Requires safety and directional signs • May cause loss of some parking appealing spaces near the intersection • Not very safe for bicyclists unless • bicycle facilities are provided • Not applicable for many residential street intersections due to space reauirements 9 SPEED CONTROL MEASURES • Not applicable for many residential street intersections due to space requirements 10 - ctk •!Z Vv. SPEED CONTROL MEASURES _• .;, •a:,'tf,.'.11;" NI 4 vantages: sthetically appealing duces pedestrian crossing 'stance educes speed without significantly impacting emergency response Disadvantages: Expensive 11 SPEED CONTROL MEASURES 1 Advantages: Provides landscaping opportunities Discourages traffic from continuing through residential streets SZO lows traffic Breaks up sight -lines on straight street Disadvantages: May direct traffic to other residential streets airly expensive 13:r_i'=_ t=c) 12 F SPEED CONTROL MEASURES Advantages: ortens pedestrian Tossing distance reates added street landscaping area Discourages truck entry isadvantages: ay cause inconvenience to local users ay ' affect bicycle mobility and safety Not very effective in reducing Speed May cause Toss of some curbside parking May require reworking of surface drainage 13 SPEED CONTROL MEASURES x 1 m ..... .. �. I3c a.1 eed Hump /Choker verter-Closure entral Island/Neckdown aised Intersection nv_ eckdown Central Island/Choker Central Island/Speed Table aised CrossinglChoker entral Island/Speed Hump 14 No. Speed Change Percent Sites After in Speed Change 2' Humps *14' Humps *22' Tables *Circles •Narrowings -Half Closures •Diverters 179 15 58 45 7 16 10 27.4 mph -7.6 mph 25.6 -7.7 30.1 -6.6 30.3 -3.9 32.3 -2.6 26.3 -6.0 27.9 -1.4 'ource: Institute of Transportation Engineers 15 -22% -23 - 18 - 11 - 4 - 19 -4 1.4 Average Change Percent in Volume Change ' Humps 143 -355 vpd 4' Humps 15 -529 Tables 46 -415 Circles 49 -293 •Narrowings 11 -263 *Half Closures 53 -1611 •Diverters 19 -501 Source: Institute of Transportation Engineers 16 -18% -22 -12 -5 -10 -42 -35 tft Change In Collision Frequency 0% - -10% -20% -30% -40% 'International Experience Traffic Speed Stop Circles Chicanes Narrowings Humps Signs (3) (2) (1) (14) (3) Multiple (25) Speed limit Refuges Reductions (2) (2) -50% - -60% -70% -80% -90% -30% -65% -82% -82% -74% -75% -70% Source: E. Geddes et al., Safety Benefits of Traffic Calming, Insurance Corporation of British Columbia, Vancouver, 1996, p. 38. umps Humps 22' =Tables Circles w/o Seattle ll Circles Overall Exclude Seattle Source: Institute of Transportation Engineers 18 -13% -40% -45% -28% -71% -51 % -25% NO NO Residents_ Concerns Petition KProbiem Identification Are Streets City Collectors or Residential Streets? YES YES Data Collection 19 GENERAL REQUIREMENTS & CONSTRAINTS • Limited to city residential collectors & local residential streets. • Posted speed limit between 30 & 35 mph. Limited to streets with only two lanes of travel. Streets are not a primary emergency routes. • May not be installed if curves streets would create an unsafe condition. • Streets are not a truck route. ▪ No adverse effect pedestrians and/or bicycles safety. • No adverse effect street drainage. :Traffic Volume` > 3,000 vpd 85th Percentile Speed > 5 mph over posted Speed Limit Cut -Through Traffic > 40% Pedestrian Volume > 25 pph Accidents > 6/year NO Traffic Volume* > 1,000 vpd 85th Percentile Speed > 5 mph over posted Speed Limit Cut -Through Traffic > 25% Pedestrian Volume > 15 pph Accidents > 3/year 20 * Volume/Speed Trade-off If the 85th Percentile Speed is greater than 5 mph over posted Speed Limit, for every 1 mph difference, 200 vpd should be added to the existing daily traffic volume. *-NO Identify Traffic Calming Alternatives Post -Implementation Study 21 INSTALL YES- PERMANENT DEVICE - Collector 22 Principal Arterial