Freeway CongestionIn The Washington Region

Presentation to

National Capital Region Transportation Planning Board

February 15, 2006

Item # 9

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FREEWAY CONGESTION MONITORING

• Background– 300 mile system monitored every 3 years since

1993 (5 surveys to date)– 3 hours in the AM and 3 hours in the PM– Photographs taken on multiple days (minimum

of 3 days) with typical, recurring conditions– Density in passenger cars per mile per lane of

freeway segments used to identify congestion– 2005 survey compared with 2002 survey and

prior surveys (1999, 1996, 1993).

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Levels of Service (LOS) Based on Density

– LOS “E and F” considered as congested

OVERALL SYSTEM PERFORMANCE

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2005 AM Peak Period

(6 AM to 9 AM)

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2005 PM Peak Period

(4:30 PM to 7:30 PM)

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2005

2002

Lane Miles at LOS F - 2002 & 2005 Survey Density > 45 Passenger car per mile per lane

(2000 Total lane miles)

164

356341

301 308

155

229

442

394

495

450

169

0

100

200

300

400

500

600

6 to 7 AM 7 to 8 AM 8 to 9 AM 4:30 to 5:30 PM 5:30 to 6:30 PM 6:30 to 7:30 PMHours

La

ne

Mile

s

2005

2002

25%

20%

15%

10%

5%

SEGMENTS WITH SIGNIFICANT CHANGES

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I-95 in Virginia / EVENING

DEGRADED CONDITIONS

(General trend toward more congestion at the HOV lane merge no significant capacity changes)

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DULLES TOLL ROAD / MORNING Addition of a fourth (HOV) lane was completed prior to the 1999 survey, resulting in improved eastbound flow; however, further LOS degradation is evident since then. (The Greenway has channeled additional traffic into this corridor.)

DEGRADED CONDITONS

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(General trend toward more congestion on the Beltway; no significant capacity changes)

DEGRADED CONDITIONSI-495 (BELTWAY) vicinity College Park / EVENING

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IMPROVED CONDITIONSUS 50 in Maryland / MORNING

Prior to the survey in 2005, an HOV lane was added to US 50 in each direction (24-hour enforcement). The additional capacity of the highway has dramatically improved traffic flow on US 50.

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I-495 (BELTWAY) vicinity Springfield / EVENING

IMPROVED CONDITIONS

(Widened exit ramps opened prior to 2005 survey)

(During the height of construction, outer loop congestion was particularly severe)

(1993-1999, extensive exit queues were found, but intermittently)

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DC 295 at US 50 / EVENING

It appears that completion of construction on US 50 has resulted in improved eastbound flow, which may now be generating downstream congestion at the DC 295 merge.

MIXED RESULTS

SIGNIFICANT CHANGE DUE TO IMPROVEMENT COMPLETED

AFTER SPRING 2005:

THE BELTWAY OUTER LOOP TO THE DULLES TOLL ROAD

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• After the Spring 2005 survey VDOT opened a second lane on the off-ramp from SB I-495 to WB VA 267.

• SKYCOMP conducted additional AM and PM flights in December 2005 and January 2006.

• The following two slides show the improvements during the AM and PM peak hour.

A SIGNIFICANT RECENT IMPROVEMENT: ADDITION OF THE SECOND LANE ON EXIT RAMP FROM I-495

TO VA 267

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I-495 Outer Loop (8 to 9 AM)I-495 Improvement due to 2nd lane on exit ramp at VA 267

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I-495 Outer Loop (5:30 to 6:30 PM) I-495 Improvement due to 2nd lane on exit ramp at VA 267

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Spring 2005 (8 to 9 AM)

Winter 2005/2006 (8 to 9 AM)

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– The addition of the extra lane on the off-ramp produced a dramatic improvement.

– Outer loop traffic which used to back up to I-270 now flows freely during the AM and PM peaks.

– The interchange downstream of the improvement has to be watched for future problems. The on-ramp from EB VA 267 and the off ramp to WB VA 123 are becoming congested due to weaving and traffic backing up from a signal on VA 123.

FINDINGS FROM THE ADDITION OF 2ND LANE EXIT RAMP TO WB VA 267 FROM SB I-495

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Freeway Segments with the Most Significant Changes (2002 to 2005)

* Density measured in passenger cars per mile per lane ** This improvement occurred after the Spring survey

Route and Direction From To LOS / Density Change *

% Change

Improvement (I) or Degradation (D)

WB I-66 (4:30 to 5:30 PM) Lee Hwy Sudley Rd F to F/(45 to 90) 100% D SB I-95 (4:30 to 5:30 PM) Dumfries Blvd Russell Rd D to F/(30 to 60) 100% D EB I-66 (6 to 7 PM) US 50 Rock Creek Pkwy C to F/(30 to 55) 80% D NB DC 295 (5 to 7 PM) Pennsylvania Rd US 50 D to F/(40 to 70) 75% D EB VA 267 (7 to 8 AM) Fairfax County Pkwy Reston Pkwy E to F/(40 to 70) 75% D IL I-495 (4:30 to 5:30 PM) I-95 Annapolis Rd E to F/(40 to 70) 75% D WB US 50 (6 to 7 AM) MD 197 Martin Luther King

Jr. Blvd. F to B/(70 to 20) 70% I

EB VA 267 (7 to 8 AM) Wiehle Ave Hunter Mill Rd F to F/(50 to 80) 60% D OL I-495 (4:30 to 5:30 PM) New Hampshire I-270 E to F/(45 to 70) 55% D SB I-270 (7 to 8 AM) Shady Grove Rd Montrose Rd F to F/(50 to 75) 50% D EB I-70 (7 to 8 AM) US 15 I-270 C to E/ (30 to 45) 50% D SB I-95 (MD) (7 to 8 AM) Sandy Spring Rd Powder Mill Rd C to E/(30 to 45) 50% D OL I-495** (8 to 9 AM and 5:30 to 6:30 PM))

I-270 Dulles Toll Rd F to D/(80 to 40) and F to D (100 to 40)

50% and 60%

I

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Top Ten Congested Segments on the Freeway System (2005)

Rank Route From To Density * Speed Range 1 IL I-495 (4:30 to 5:30 PM) I-270 Connecticut Avenue 130 5 to 10 MPH 1 NB I-395 (5 to 6 PM) VA 110 GW Pkwy 130 5 to 10 MPH 3 NB I-95 (6 to 8 AM) Dale Blvd Prince William Pkwy 125 7 to 15 MPH 4 IL I-495 – (6 to 7AM ) St Barnabas Rd I-295 120 8 to 15 MPH 5 WB Frederick Douglass and 11th

Street Bridges – (8:30 to 9:30 AM) Anacostia Bridges 115 10 to 15 MPH

6 NB I-395 (7:30 to 8:30 AM) VA 110 GW Pkwy 105 12 to 20 MPH 7 NB I-295 (7:30 to 8:30 AM) Suitland Pkwy 11th Bridge 100 14 to 20 MPH 7 GW Pkwy (7:30 to 8:30 AM) Spout Run Key Bridge 100 14 to 20 MPH 7 EB I-66 – (6 to 7 PM) Dulles Toll Rd Westmoreland St 100 14 to 20 MPH 7 EB US 50 – ( 5 to 6 PM) I-95/I-495 Martin Luther King Jr. Blvd. 100 14 to 20 MPH * Density measured in passenger cars per mile per lane

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Overall Study Findings

– Total lane miles of congestion have increased significantly since 2002 throughout both the AM and PM peak periods, with the greatest increase (64%) in the first hour of the PM peak (4.30 to 5.30pm).

– Congestion is generally in the peak travel direction only during AM and PM peak periods. Exceptions are the 14th street bridge (AM and PM), I-66 inside the Beltway (AM and PM), the Wilson Bridge (AM), and the northwestern portion of the Beltway (PM) which are congested in both directions.

– Capacity increases have improved conditions at certain locations (US 50, Springfield Interchange, Capital Beltway at Dulles Toll Road).

– Locations downstream of major improvements need to be monitored for potential future problems.

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Tackling Recurring Freeway Congestion – Short Run

Capacity Increases To Address Bottlenecks• Adequate freeway to freeway, freeway to

arterial, and arterial to freeway connections• High Occupancy Toll (HOT) or Express

Toll Lanes (ETL)

Transit and Demand Management• Adequate transit funding and capacity• Ridesharing and telecommuting

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Tackling Recurring Freeway Congestion – Longer Run

Alternative Land Use/Transportation Futures(Regional Mobility and Accessibility Study)

More Households in Activity Centers– More households in the region located in regional activity centers– Supporting transit improvements

Region Undivided– Some job and household growth shifted from West to East– Supporting transit improvements