US Bridges

Mount Street over I-170

Fair

Baltimore city, Maryland · 0.1 MI N of Saratoga ST · Structure no. 200000BC1504010

Built
1976
49 years old
Condition
Fair
inspected June 2024
Type
Box Beam or Girders - Single or Spread
Concrete Continuous
Length
198 ft
3 main spans
Daily traffic
3,243
2024 count
Owner
City
City or Municipal Highway Agency

About this bridge

Mount Street over I-170 is a concrete continuous box beam or girders - single or spread carrying Mount Street over I-170 in Baltimore city, Maryland. It was built in 1976, so it is 49 years old, younger than the Maryland average of 52.6 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 3,243 vehicles a day, roughly 5% of them trucks, projected to reach 3,956 by 2044. The structure is 198 ft (60.4 m) long and 70 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesMount Street
CrossesI-170
Location0.1 MI N of Saratoga ST
RouteCity Street 0
CountyBaltimore city
StateMaryland
Coordinates39.29369, -76.64419
Functional classUrban Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60.5 US tons
Inventory rating36 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length198 ft (60.4 m)
Longest span73 ft (22.3 m)
Deck width70 ft (21.3 m)
Roadway width52 ft (15.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,243 (2024)
Projected traffic3,956 by 2044
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$78,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was Mount Street over I-170 built?

It was built in 1976, making it 49 years old in 2025.

What condition is Mount Street over I-170 in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in June 2024.

How much traffic does Mount Street over I-170 carry?

About 3,243 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is Mount Street over I-170?

The structure is 198 ft (60.4 m) long with a longest span of 73 ft (22.3 m) and a deck 70 ft wide.

Who owns Mount Street over I-170?

It is owned by the City or Municipal Highway Agency.