Grade Separation Alternative A Feasibility Analysis of the Reconfiguration of Genesee Avenue at Governor Drive By: Daniel Aruta, P.E.

Topics for Discussion: What is a Grade Separation? Construction Impacts Traffic Analysis Environmental Impacts

PART 1: What is a Grade Separation? A facility which provides a physical vertical separation between two roadways crossing each other to alleviate traffic congestion and promote safety One roadway passes over another crossing roadway, and both roadways do not meet The upper roadway crosses over the lower roadway via a bridge Similar to a diamond interchange on a freeway A Grade Separation is not a tunnel! University Avenue in Park Slope

Sample of a Grade Separation Diamond Interchange of Interstate 15 at El Cajon Blvd in San Diego El Cajon Blvd Off Ramp Interstate-15

5 Basic Elements of a Grade Separation Interstate 15 at El Cajon Blvd in San Diego Bridge Retaining Wall Retaining Wall Ramp Depressed Roadway

5 Basic Elements of a Grade Separation Interstate 15 at El Cajon Blvd in San Diego Retaining Wall Bridge Retaining Wall Ramp Depressed Roadway

Genesee Ave Grade Separation at Governor Dr Bridge on Governor Dr passes over Genesee Ave below 2 Lanes on Genesee Ave are depressed to pass under the bridge 4 Ramps Inside Retaining Walls (4 each) Outside Retaining Walls (minimum of 4 each) Total Length from end to end = 1,787 ft. Begin Walls Begin Walls North Inside Retaining Wall Depressed Roadway Ramp Outside Retaining Wall Bridge Plan View

Vertical Scale is Exaggerated! Begin Grade Separation Vertical Separation Governor Dr above Genesee Ave 2 inside lanes of Genesee Ave below Governor Dr A bridge over a depressed roadway Vertical Scale is Exaggerated! Existing Roadway Governor Drive Genesee Depressed Roadway Avenue Begin Grade Separation End Grade Separation Vertical Profile View

Section Through Bridge Section where Genesee Ave passes under the bridge at Governor Dr Length of Bridge (Span) = > 50 ft. Width of Bridge = ± 110 ft. Section View

Section Through Retaining Walls Section of Genesee Ave north and south of Governor Dr (beyond bridge) Section View

Lengths of Retaining Walls Inside Retaining Walls: South of Governor Dr: 731 ft. long, max height greater than16.5 ft. North of Governor Dr: 936 ft. long, max height greater than16.5 ft. North 731’ 936’ Plan View

Part 2: Construction Impacts Utility Relocation Constructing the Bridge Constructing the Retaining Walls Road Closures Environmental Impacts Project Duration

Utility Relocation N Two 16” Water Mains 8” Sewer Electrical Duct Bank Gas Line Phone Cables Water Phone Elect Gas Sewer Governor Dr Water Phone Genesee Ave

Constructing the Bridge Drive Sheet Piling into the Ground Sheet Piling Section View

Constructing the Bridge Drive Sheet Piling into the Ground Excavate Pit for the Bridge Section View

Constructing the Bridge Drive Sheet Piling into the Ground Excavate Pit for the Bridge Construct the Bridge Section View

Constructing the Retaining Walls Drive Sheet Piling into the Ground Excavate Channel Construct Inside Retaining Walls and Depressed Roadway Construct Outside Retaining Walls for Sideslopes and Outside Roadways Section View

Extent of Sheet Piling in Genesee Ave For Depressed Roadway: Approx. 1,100 ft. each side of depressed road For Outer Retaining Walls: Lengths will vary North Depressed Roadway Sheet Piling Plan View

Environmental Impacts to Consider During Construction Noise Vibration Air Quality Truck Trips Contaminated Soils Example Backup Bells on Construction Equipment Driving Sheet Piling Diesel Exhaust from Construction Equipment Thousands of Truck Trips Soils Mitigation from 4 Gas Stations – Project Delay

Project Duration Utility Relocation = 6± months Mitigation of Contaminated Soils = ? Construction of Grade Separation = 2± years Total Project Duration = 2.5+ years

Road Closures during Construction Genesee Ave from Radcliff La to south of University City HS Intersection of Governor Dr and Genesee Ave Disruption to Vehicular and Pedestrian Traffic Loss of Access to Schools and Businesses Economic Hardship on Local Businesses Huge Detriment to the Community North 1,800 ft. Plan View

North/South Access during Construction No Bridge on Regents Rd 1,800 ft. of Genesee Ave closed Intersection of Governor Dr and Genesee Ave closed Police, Fire and Paramedic Service to University City will be severely challenged during construction

Alternate Routes during Construction Interstate 5 Freeway Interstate 805 Freeway State Route 52 Detour!

Part 3: Traffic Analysis – Post Construction Existing Traffic Movements at Intersection of Genesee & Governor Proposed Traffic Movements at Intersection of Genesee & Governor Level of Service and Lane Reductions at Split Points Elimination of Bus Stops

Existing N-S Traffic Lanes at Intersection 2 Southbound Through Lanes 2 Left Turns – SB Genesee to EB Governor 1 Southbound Right Turn 2 Northbound Through Lanes 1 Left Turn – NB Genesee to WB Governor 1 Northbound Right Turn Existing Intersection

Proposed N-S Traffic Lanes at Intersection 1 Southbound Combined Through/Right Turn Lane 1 Left Turn – SB Genesee to EB Governor 1 Northbound Combined Through/Right Turn Lane 1 Left Turn – NB Genesee to WB Governor Grade Separation

UC Golden Says: …and… Do The Math: NB: 78% of 33,000 = 25,740 ADT SB: 70% of 33,000 = 23,100 ADT

Street Classification and Level of Service (LOS) Level of Service “E” = 10,000 ADT for 1 Lane NB Traffic: 25,740 ADT > 10,000 ADT SB Traffic: 23,100 ADT > 10,000 ADT NB: 2.57 x Failure Volume SB: 2.31 x Failure Volume

Lane Reduction at Split Point Decision: Do I take the underpass or do I take the ramp to Governor Dr? “Governor Dr ” As most cars from two lanes vie for position into one lane, this will effectively create a “lane reduction” at the split point and traffic will back up! Split Point UC Golden: 1 Through Lane Ramp to Governor Dr

3 Bus Stops on Genesee Ave are Eliminated Post Construction

Part 4: Environmental Impacts – Post Const. Noise Neighborhood Character Tree Removal

Noise Sound acoustics are accentuated off retaining walls Increase in traffic volumes over time due to urban growth will increase ambient noise levels

Neighborhood Character University City is a residential community Only small retail except for commercial district on Greenwich Dr UC is not a major traffic generator like Golden Triangle Grade Separation will “urbanizes” the character of the neighborhood Should future University City appear like this?

Tree Removal 88 Conifer Trees 22 Eucalyptus Trees 5 Sycamore Trees 3 Others 118 trees will be removed

The End