1. MULTIMODAL ACCESSBILITY

2. 1 2 3 1 PHYSICS OF CITIES – SCIENCE OF ACCESSIBILITY 2 2 A NEW ACCESSIBILITY FRAMEWORK 3 PRESENTATION OVERVIEW ACCESSIBILITY APPLICATIONS

3. 1 THE PHYSICS OF CITIES Yes Virginia, there is a science behind this 3

4.  In the natural world, gravity warps the space-time continuum  Gravity compresses (slows) time  In cities, density (urban gravity) warps the distance-time continuum  Time stays constant and limited  Distance between places varies  Density compresses distance  Speed decompresses distance THE PHYSICS OF CITIES ACCESSIBILITY SCIENCE High gravity Compressed space-time

5. Number of needed and preferred opportunities (city design elements) within a reasonable amount of time (design target)  Travel to work  Long commutes impact quality of life Commute time to work averages around 20 to 25 minutes  Long commutes impact economic development Employers locate where needed employees are within reasonable commute times  Non-work travel  Nearby retail and services impact neighborhood quality Wegmens, food desert phenomena  Retailers live and die by accessibility to roof-tops I.e., groceries require around 3,000 rooftops within 10 minutes ACCESSIBILITY MEASURES DENSITY (URBAN GRAVITY) ACCESSIBILITY SCIENCE 5 “I was dealing with at least two hours a day of stress.” Two weeks ago, Greene took a new job about 10 minutes from home. “It’s liberating,” she says. “I can make dinner plans. I am so much happier.” Miami Herald, May 5, 2015

6. Where: OPPORTUNITIES = Number of Jobs (HBW) or Number of Retail/Service Establishments (HBNW) TRAVEL TIME = Time to reach opportunity over actual network (Network Analyst) DECAY* = Factor reflecting decrease in value of opportunities that are farther away MEASURING ACCESSIBILITY ACCESSIBILITY SCIENCE 6

7. ACCESSIBILITY – REASONABLE TIME (TIME DECAY) ACCESSIBILITY SCIENCE 7  Opportunities further away have less value  The value, or decay, is consistent and strong ( results from WashCOG travel survey)  Decay varies by:  Trip purpose  Travel mode DECAY CURVES

8. ACCESSIBILITY – TRAVEL TIME & DISTANCE AND SPEED Average Commute Distance (mi)Speed (mph) 13 26 39 412 515 618 721 824 927 1030 1133 1236 1339 1442 1545 1648 1751 1854 1957 2060 8  Reasonable commute time = 20 minutes  A destination one mile away requires an average speed of 3 mile per hour  A destination 10 miles away requires 30 mph  A destination 20 miles away requires 60 mph TIME TARGET ACCESSIBILITY SCIENCE

9. ACCESSIBILITY – NEEDED AND PREFERRED OPPORTUNITIES 9  Assume average accessibility target of 10,000  CBD location meets target in 1 mile  Fringe location meets target in 12 miles  Speed is needed to overcome low densities ACCESSIBILITY TARGET High density Low density 10,000 score ACCESSIBILITY SCIENCE

10. ACCESSIBILITY DESIGN STRATEGIES ACCESSIBILITY SCIENCE 10  Strategies to meet travel time target  Both examples assume 25 minute travel time target  Mobility example requires 31 mph speed to cover 13 miles  Proximity example requires 20 mph to cover 8 miles MOBILITY vs PROXIMITY Mobility model (lower densities, higher speeds) Local Collector Arterial Expressway Home Work Same times but different speeds and distances Proximity model (higher densities, lower speeds) Home Work

11. ACCESSIBILITY DESIGN STRATEGIES ACCESSIBILITY SCIENCE 11  Walk the slowest mode, hence requiring the highest density  Auto the fastest mode, hence providing density trade-off  Auto speed heavily influenced by network design (later) ALTERNATIVE TRAVEL MODES

12. DISTANCE, SPEED AND MODE Average Commute Distance (mi)Speed (mph) 13 26 39 412 515 618 721 824 927 1030 1133 1236 1339 1442 1545 1648 1751 1854 1957 2060 12  Reasonable commute time = 20 minutes  Walk speed requires opportunities within 1 mile  Bike speed 5 miles  Transit speed 8 miles  Auto speed 14 miles+ DISTANCE AND SPEED IMPACT MODE ç Walk Bike Premium transit Auto

13. ç Walk Bike Premium transit Auto ACCESSIBILITY, SPEED AND MODE ACCESSIBILITY SCIENCE 13  CBD has enough opportunities to make walking viable  Walk, bike and transit modes don’t provide enough speed to reach target opportunities from fringe location TRAVEL MODE VIABILITY 10,000 score

14. THE SCIENCE PLAYS OUT EVEN IN TODAY’S AUTO ORIENTED WORLD ACCESSIBILITY SCIENCE 14  Very few in Manhattan own a car  Yet incomes are among the highest in the country  Density provides enough access to make walking viable  Cars take up space, reducing density HOUSEHOLDS WITHOUT A CAR

15. 2 A NEW FRAMEWORK Expanding the focus beyond transportation facility levels of service 15

16. CITY DESIGN FOCUSES ON SPEED ACCESSIBILITY FRAMEWORK 16 Roadway level of service measures the impact of congestion on speed Key assumption is: as speed drops, so does accessibility Given the influence of density, is that always true? ROADWAY LEVEL OF SERVICE (LOS)

17. DESIGNING FOR SPEED 17  Red indicates severe congestion  Lightest green indicates moderate to no congestion  Most roads congested, focusing attention on added capacity  Focus drains limited funding  But will those improvements really help? ROADWAY LEVEL OF SERVICE Most congestion along I- 270 and I-95 corridors Heavy congestion on and around the beltway Most congestion along I- 270 and I-95 corridors Heavy congestion on and around the beltway ACCESSIBILITY FRAMEWORK

18. DESIGNING FOR ACCESS 18  Auto accessibility is baseline for establishing levels of service  Average weighted access score is LOS C  LOS A and B is better than average  LOS D, E and F worse than average UNCONGESTED ACCESSIBILITY Access rings around DC urban gravity (density) Speed provides access along I-270 and I-95 Lower order magnitude gravity rings around Frederick Access rings around DC urban gravity (density) Speed provides access along I-270 and I-95 Lower order magnitude gravity rings around Frederick A B C D E ACCESSIBILITY FRAMEWORK

19. DESIGNING FOR SPEED 19  Accessibility scores rerun with congested versus uncongested speeds  Results indicate biggest impacts away from urban gravity (density) CONGESTED ACCESSIBILITY LOS A ring near DC doesn’t change much except along I-270 and I-95 LOS B area pulls in dramatically around DC (reflecting the weight of density over speed) Frederick drops from D to E (economic impacts?) LOS A ring near DC doesn’t change much except along I-270 and I-95 LOS B area pulls in dramatically around DC (reflecting the weight of density over speed) Frederick drops from D to E (economic impacts?) A B C D E ACCESSIBILITY FRAMEWORK

20. DESIGNING FOR SPEED 20  Focus on roadways suggests area along beltway is highly congested, yet accessibility remains A  Without accessibility context, agencies focus on fixing congested roads, regardless of location  Focus leads to wrong projects and funding priorities ACCESSIBILITY VS ROADWAY LOS Roadway congestion highest in A accessibility area Congestion along I-270 and I-95 causing drop along those corridors Roadway congestion highest in A accessibility area Congestion along I-270 and I-95 causing drop along those corridors A B C D E ACCESSIBILITY FRAMEWORK

21. DESIGNING FOR SPEED 21  Transit accessibility LOS on same scale as auto LOS accessibility  Improving transit LOS a heavy funding lift  Most of corridor has extremely poor transit accessibility  Several locations close to DC and along Metro rail have LOS A TRANSIT ACCESSIBILITY Transit access LOS A only in areas with premium transit and transit oriented development Areas with LOS A also have non-auto mode shares greater than 50% Transit access LOS A only in areas with premium transit and transit oriented development Areas with LOS A also have non-auto mode shares greater than 50% A B C D E ACCESSIBILITY FRAMEWORK

22. 3 APPLYING ACCESSIBILITY What we’ve learned so far 22

23. SHIRLINGTON WALK DEMAND – NCHRP 770 APPLICATION ACCESSIBILITY APPLICATIONS New link results in 500 new walk trips

24. ASHEVILLE ACCESSIBILITY FOR LOW INCOME NEIGHBORHOODS ACCESSIBILITY APPLICATIONS Problem: limited access to food stores for southern portion of study area Best solution: provide new food market! Existing markets too far for walking

25. DC ACCESSBILITY BASED LOCATIONS FOR LOW INCOME HOUSING ACCESSIBILITY APPLICATIONS

26. MDOT MODE SHARE ESTIMATION ACCESSIBILITY APPLICATIONS

27. WASHCOG GHG MODELING ACCESSIBILITY APPLICATIONS 27

28. MULTIMODAL ACCESSBILITY

29. Interplay between travel time and cost  Accessibility has value More access, creates more opportunities  Access trade off with land values and rents Steady drop from metro center (concentric ring theory)  Metro equilibrium curve Some value time, others value space “Drive till you qualify”  High speed, high capacity transportation modifies access contours Radial corridors stretch access from metro center (sector theory) Circumferential corridors (belt routes) intersecting with radial routes create high access centers (edge cities) (multiple nuclei theory)  Modified access contours create consistent metropolitan patterns Circus tent (central place theory) ACCESSIBILITY SHAPES METRO AREAS ACCESSIBILITY PLANNING 29 Show Houston / Beijing patterns or Washington circus tent

30. As an element changes, others respond  Accessibility has value More access, creates more opportunities  Access trade off with land values and rents Steady drop from metro center (concentric ring theory)  Metro equilibrium curve Som “Drive till you qualify”  High speed, high capacity transportation modifies access contours Radial corridors stretch access from metro center (sector theory) Circumferential corridors (belt routes) intersecting with radial routes create high access centers (edge cities) (multiple nuclei theory)  Modified access contours create consistent metropolitan patterns Circus tent (central place theory) METRO AREAS SEEK EQUILIBRIUM ACCESSIBILITY PLANNING 30 Show patters

31. ACCESSIBILITY PLANNING Access to an opportunity is the product of mobility (travel speed) and proximity (land use) ACCESSIBILITY INTEGRATES TRANSPORTATION AND LAND USE 31 MOBILITY (NETWORK) PROXIMITY (LAND USE) ACCESSIBILITY (OPPORTUNITY)

32. ACCESSIBILITY PLANNING ACCESSIBILITY IS INFLUENCED BY TRANSPORTATION AND LAND USE 32 Closer destinations allow slower speeds to attain reasonable travel time At slower speeds (around 25 mph), all of the network is in play Further destinations require higher speeds, At higher speeds (over 35 mph) only high speed facilities are in play Mobility and proximity are accessibility strategies Mobility model (lower densities, higher speeds) Local Collector Arterial Expressway Home Work Same times but different speeds and distances Proximity model (higher densities, lower speeds) Home Work