1. September 15, 2011 Presented by: Clay Harris, PMP - City of Austin Federico Mendoza, PE, PTOE – Brown & Gay Engineers, Inc. Todd Lane Alternative Geometric Design Study Ben White to St. Elmo Austin, Texas

2. Project History Todd Lane Alternative Geometric Design Study Austin, Texas 2

3. Critical Goals and Concerns Enhance Vehicular and Pedestrian Safety Maintain acceptable Level of Service Improve Corridor Appearance Pursue Code Compliance –Street, pedestrian, signage, etc. Stimulate Revitalization Maintain Commercial Activity during construction 3

4. Original Project Design Alternative 1 –4-lane divided on Todd Lane –4-lane divided boulevard on Pleasant Valley Road –Standard signalized intersection at Todd Lane and St. Elmo Road Todd Lane Alternative Geometric Design Study Austin, Texas 4

5. Alternate Design Alternative 2A –3-lane roadway section on Todd Lane –4-lane divided on Pleasant Valley Road; Single-lane NB approach –Single-lane Roundabout at Todd Lane and St. Elmo Road –Fits within existing ROW Todd Lane Alternative Geometric Design Study Austin, Texas 5

6. Todd Lane Alternative Geometric Design Study Austin, Texas Roundabout Benefits Improved pedestrian and vehicular safety Elimination of left-turn, head-on, and T-bone collisions Vehicle-vehicle conflicts decreases from 32 to 8 Crash reduction: –90% fatal crashes, 76% injury crashes, 35% overall Yield operation promotes minimal queuing Significant reduction in delay Opportunity for community landmark 6

7. Todd Lane Alternative Geometric Design Study Austin, Texas Study Scope Traffic Volumes Single-Lane Roundabout Concept Layout Two-Lane Roundabout Concept Layout Truck Vehicle Paths Traffic Simulation Analysis Conclusions 7

8. Traffic Volumes Existing Peak Hour Volumes – Todd Lane at St. Elmo Rd. –AM Peak: Heavier Volumes –PM Peak: Relatively Balanced Flows Todd Lane Alternative Geometric Design Study Austin, Texas 8 Approach AM Peak Hour (Vehicles per hour) PM Peak Hour (Vehicles per hour) Northbound-- Southbound301474 Eastbound458523 Westbound677327 Total1,4361,324

9. Traffic Projections Derived from Existing Counts and CAMPO Estimates Daily Traffic Volume Forecasts – Todd Lane at St. Elmo Road Todd Lane Alternative Geometric Design Study Austin, Texas 9 Intersection Leg 2015 Daily Volumes (Vehicles per day) 2025 Daily Volumes (Vehicles per day) 2035 Daily Volumes (Vehicles per day) North11,10014,00018,000 South11,40015,40015,500 East3,3705,5187,000 West9,1008,5007,900

10. Todd Lane Alternative Geometric Design Study Austin, Texas Single-Lane Roundabout Concept Google 2009 10

11. Todd Lane Alternative Geometric Design Study Austin, Texas WB-50 Design Vehicle 11

12. Todd Lane Alternative Geometric Design Study Austin, Texas WB-50 Design Vehicle 12

13. Traffic Simulation Results – Year 2025 Todd Lane Alternative Geometric Design Study Austin, Texas Peak Hour PeriodApproach Intersection Delay Alternative 1Alternative 2A Standard Intersection Single Lane Roundabout AM PEAK Northbound50.910.4 Southbound17.38.0 Eastbound63.14.4 Westbound90.662.8 ALL53.820.1 PM PEAK Northbound37.04.9 Southbound38.49.8 Eastbound29.217.5 Westbound31.96.5 ALL34.910.0 13

14. Traffic Simulation Results – Year 2035 Todd Lane Alternative Geometric Design Study Austin, Texas Peak Hour PeriodApproach Intersection Delay Alternative 1Alternative 2B Standard Intersection Two Lane Roundabout AM PEAK Northbound57.338.8 Southbound21.06.1 Eastbound75.422.0 Westbound105.1112.6 ALL63.052.6 PM PEAK Northbound41.07.2 Southbound41.97.0 Eastbound33.910.4 Westbound52.47.0 ALL40.98.4 14

15. Vissim Micro-simulation: 2025 AM Peak Todd Lane Alternative Geometric Design Study Austin, Texas 15

16. 2025 AM Peak – Signal vs. Roundabout Todd Lane Alternative Geometric Design Study Austin, Texas 16

17. Project Schedule Alternate Design –Complete Real Estate Acquisition - Fall 2011 –Begin Design Fall 2011 –Complete Design Fall 2012 –Begin construction – Spring 2013 17

18. Conclusions The single-lane roundabout will provide: –Acceptable level of service through year 2025 during peak hours –Least amount of delay to motorists during off-peak hours –Higher level of safety (reduction in crashes) for vehicles –Higher level of safety for pedestrians and bicyclists –A safe and efficient alternative to a standard signal that will fit within the R.O.W. footprint Todd Lane Alternative Geometric Design Study Austin, Texas 18

19. Questions? Comments? Clay Harris, Project Manager Public Works Department Call 512-974-7895 Email clay.harris@ci.austin.tx.usclay.harris@ci.austin.tx.us 19