Maryland’s State Highway Administration has moved the MD 4 and Suitland Parkway interchange into a new long-term traffic pattern as of August 17, 2026. Drivers who use Pennsylvania Avenue through Upper Marlboro now face a construction-phase layout expected to last about two years while crews build a diamond interchange.
For Prince George’s County commuters and travelers linking Joint Base Andrews, Suitland, and east-county corridors, the decision is simple and immediate. Rebuild the morning and evening route clock with extra buffer, learn the temporary dual-lane pattern, and do not treat the old merge habits as current truth.
- What changed: A new traffic pattern is in place on MD 4 at the Suitland Parkway interchange.
- Start: Pattern expected open the morning of August 17, 2026, after a temporary weekend access closure.
- Duration: About two years while diamond-interchange construction continues.
- Lane shape: Two lanes in both directions, with dual left-turn lanes kept on northbound MD 4 to Suitland Parkway.
- Project scale: Local reporting places the interchange work inside a roughly $238 million diamond-interchange project.
What MDOT SHA announced about the shift
According to the Maryland Department of Transportation State Highway Administration press release, SHA implemented a new traffic pattern as the MD 4 at Suitland Parkway Interchange project in Prince George’s County enters its next construction phase. The release is dated August 11, 2026, and points to an August 17 pattern opening after temporary weekend work.
SHA said crews would install traffic infrastructure, including electronic and directional signage, during a temporary weekend closure of access to Suitland Parkway from northbound MD 4 on August 14 to 16 starting at 7 p.m., weather permitting. The new pattern was expected to open the morning of August 17 and remain for approximately two years.
The official notice also states the new traffic pattern will consist of two lanes in both directions while maintaining dual left-turn lanes on northbound MD 4 to Suitland Parkway. That detail matters for drivers who used different left-turn storage or merge habits under the prior phase.
What local reporting adds for daily travelers
NBC4 Washington reporting published August 16, 2026 described the change as a major traffic shift for Prince George’s County commuters using MD 4 at Suitland Parkway in Upper Marlboro. The station linked the pattern to a roughly $238 million diamond-shaped interchange project and advised drivers to leave a little earlier.
That independent report does not replace SHA’s construction sequence, but it confirms the traveler impact in plain commute language. Drivers who only scanned social video should still read the official lane description rather than guessing from a 60-second clip.
Local interviews in the NBC package also capture the practical reaction many residents already have: some will avoid the corridor when possible. Avoidance only works if you know alternate routes that still reach Suitland Parkway, Andrews, and east-county job centers without creating a second bottleneck.
How the two-year pattern changes trip planning
A two-year temporary pattern is long enough to become the new normal for school-year and winter travel. If you only visit Maryland for airport, base, or family trips a few times a year, assume the construction layout is still there unless SHA publishes a later phase change.
GPS apps can lag real lane assignments after a major switch. When you first drive the corridor after August 17, slow early, read temporary electronic signs, and do not force a left from a lane that no longer serves that movement.
Airport-bound drivers using MD 4 as part of a regional path should add buffer on both arrival and departure days. A construction-phase dual left that feels unfamiliar can erase the last 10 minutes of a tight flight plan even when free-flow traffic looks fine on a map.
What to do before your next Upper Marlboro trip
Recheck SHA project and press pages for any weekend-only restrictions that sit on top of the long-term pattern. The August 14 to 16 access closure was a short installation window, but later utility or paving nights can still appear.
Identify one alternate corridor you will actually use if MD 4 queues worse than expected. An alternate you have never driven is not a real contingency plan.
If you are staying near the capital region and combining road and air travel, keep destination planning separate from the interchange delay. Deep Arrival’s Philadelphia things-to-do guide is not a Maryland detour map, so use local SHA guidance for the road decision and destination pages only after the drive plan is honest.
For travelers connecting through other Mid-Atlantic cities, keep hotel check-in buffers honest as well. A late construction slowdown on MD 4 can cascade into missed restaurant reservations even when the rest of the day looked open.
Also tell rental-car drivers and rideshare passengers what to expect. Out-of-area drivers following only turn-by-turn audio are the most likely group to miss temporary left-turn geometry.
School-year drop-offs and pickup windows will feel this change first. Parents who timed Maryland 4 to the minute under the old merge pattern should rebuild the first two weeks with an earlier departure rather than testing the new geometry on the first late morning of class.
Freight and contractor traffic can also make mid-morning less empty than map models suggest. If your schedule allows, shift non-urgent trips away from the traditional peak pairs until you have driven the dual-lane layout once in daylight.
When a later SHA phase changes the temporary pattern again, treat that notice as a new decision, not a return to 2025 habits. Two years is long enough for multiple intermediate lane switches inside the same project name.
| If you… | What to do |
|---|---|
| Commute MD 4 at Suitland Parkway daily | Add morning and evening buffer and relearn dual-lane plus dual left-turn geometry. |
| Only drive the corridor occasionally | Assume the construction pattern lasts about two years and recheck signs every visit. |
| Need northbound lefts onto Suitland Parkway | Confirm dual left-turn lanes remain available under the new pattern before the move. |
| Can reroute without major delay | Practice one alternate path now rather than inventing it in stopped traffic. |
| Follow only phone navigation | Slow early and trust temporary SHA signage over stale map lane assumptions. |
- Now live: The August 17 long-term pattern is the current driving reality at MD 4 and Suitland Parkway.
- Duration: About two years of construction-phase lane geometry is expected.
- Turn movements: Dual left turns remain on northbound MD 4 to Suitland Parkway under SHA’s description.
- Next check: Watch MDOT SHA updates for later phase changes or night work on top of the base pattern.
MD 4 at Suitland Parkway is no longer in a short weekend detour. It is in a multi-year construction pattern that starts with August 17. Leave earlier, relearn the turns, and treat SHA’s two-year timeline as the default until a later phase notice says otherwise. One careful first drive in daylight is worth more than three rushed peak-hour experiments.
When did the new MD 4 traffic pattern start?
SHA expected the new pattern to open the morning of August 17, 2026, after temporary weekend installation work.
How long will it last?
SHA said the pattern would remain in place for approximately two years while construction continues.
How many lanes are open?
The official notice describes two lanes in both directions, with dual left-turn lanes maintained on northbound MD 4 to Suitland Parkway.
Why is the work happening?
It is the next phase of the MD 4 at Suitland Parkway Interchange project, described in local reporting as a diamond-interchange build.
What should occasional visitors do?
Add buffer, follow temporary signs, and do not assume pre-August 17 merge habits still apply.
