Maryland/Maryland Highway Classification

Maryland mappers are working on an effort to streamline highway classifications in Maryland following the 2021 Highway Classification Guidance criteria. The new approach is centered around the philosophy that "The set of roads tagged highway=motorway or highway=trunk should collectively form a coherent network of interconnected roads, without dangling spurs or "islands" of disconnected roads. This connectivity principle should also hold true as each subsequently lower classification of road is added to the network, from highway=primary through highway=tertiary. Roads should not be downgraded merely due to a road’s decreased vehicular capacity through less-settled areas."

Motorway

Example of motorway

Guidance

The top category, highway=motorway should only be applied to roadways that are either signed Interstate highways or have ALL of the following characteristics:

• Grade separation
• Limited access via on/off ramps
• No at-grade intersections or traffic signals (although on-ramps may have traffic control devices)
• Divided carriageways
• Designed and maintained to support high speeds over long distances as part of an interconnected motorway network

Maryland Motorways

In Maryland, there are 18 Interstate highways, (5 two-digit, 10 three-digit, and 3 three-digit-suffix) totaling over 530 miles of roadway. Each of these is already tagged as a motorway so no additional action is required.

Maryland Highways that meet all the five criteria but are not signed Interstates include routes such as MD-295 and US-340. A full list of these routes are listed below.

Trunk

Example of urban trunk road

Example of rural trunk road (US-7)

Guidance

As the top non-motorway classification, highway=trunk should be applied in the following cases:

• In areas of high population density, to expressways that meet most, but not all, of the requirements for highway=motorway, and provide connectivity between motorways and other trunk roads. These roads should also be tagged expressway=yes.
• In areas of medium to low population density, to the most important non-motorway roads that provide principal, long-haul connections between population centers of regional importance.

Maryland Trunks

Much of the Maryland core, which runs along the I-95 corridor and includes Washington DC and Baltimore is already well connected with Interstate highways. In the rural, lower-density areas of the Eastern Shore and Western Maryland, highways that connect a major population center or one of regional importance (see below) either in the state or in an adjacent state should be classified trunk.

Primary

Guidance

This second-level of non-motorway roads should be applied to higher-importance roads that aren’t part of the highway=motorway|trunk network. This may include US highways, business loops on the interstate network, higher-importance state roads, and roads which provide connectivity to minor population centers. In addition, this classification should be used for less-important alternative routes to inter-city connections tagged highway=motorway|trunk. In urban areas, highway=primary should be used on the main surface streets through suburbs and the tag should be used on streets reasonably spaced on a grid system.

Secondary and below

Work in progress, Dec. 2021

Tables

Interstates in Maryland

Number	Length (mi)	Relation
I-68	81.09	1404729 1404729
I-70	93.62	943157 943157
I-81	12.08	1319515 1319515
I-83	34.5	1216551 1216551
I-95	109.01	396363 396363
I-97	17.62	403161 403161
I-195	4.35	549783 549783
I-270	32.6	1603596 1603596
I-270Y	2.1	1685926 1685926
I-295	0.8	1694955 1694955
I-370	2.54	5242591 5242591
I-395	1.33	1287107 1287107
I-495	41.09	1355085 1355085
I-595	19.97	2309298 2309298
I-695	51.46	543510 543510
I-795	8.99	549880 549880
I-895	14.87	1603598 1603598
I-895A	0.71	2997725 2997725
I-895B	2.67	2997727 2997727

Motorway by Characteristics

This is a work in progress as of December 2021. This is originally sourced via MDOT SHA's list of bicycle restricted routes, a good indicator of a motorway-type route.

County	Route Prefix	Route #	Road Name	Beginning MP	End MP	Notes
Allegany	MD	61	Canal Parkway	0.00	1.94
Allegany	US	40	N/A	0.00	13.62	Same as I-68
Anne Arundel	MD	4	Southern MD Blvd	0.00	4.31
Anne Arundel	MD	10	Arundel Expressway	0.00	7.17
Anne Arundel	MD	32	N/A	0.00	6.08
Anne Arundel	MD	32	Patuxent Freeway	8.39	11.46
Anne Arundel	MD	100	N/A	0.00	13.99
Anne Arundel	MD	295	B/W Parkway	0.00	15.10
Anne Arundel	US	50	John Hanson Highway	0.00	19.88	Same as I-595
Baltimore	MD	43	White Marsh Blvd	0.00	5.28
Baltimore	MD	702	Southeast Freeway	0.00	2.05
Calvert	MD	4	Solomon's Island Road	36.43	35.72
Carroll	US	40	National Pike	0.00	1.61	Same as I-70
Cecil	US	301	Blue Star Mem. Highway	0.00	3.14
Fredrick	MD	26	Liberty Road	0.00	0.54
Fredrick	US	15	Catoctin Mt. Highway	5.25	16.53
Fredrick	US	40	Baltimore National Pike	13.17	29.24
Fredrick	US	340	Jefferson National Pike	0.00	10.03
Garrett	US	40	National Pike	13.70	30.89
Howard	US	29	Columbia Pike	1.38 NB & .63 SB	13.61
Howard	US	40	Baltimore National Pike	0.00	13.62
Howard	MD	32	Patuxent Freeway	0.00	15.92
Howard	MD	100	N/A	0.00	7.51
Kent	US	301	Blue Star Mem. Highway NB	0.00	0.19
Kent	US	301	Blue Star Mem. Highway	7.73	8.79
Montgomery	MD	200	Intercounty Connector	2.54	17.21
Montgomery	US	29	Columbia Pike	4.35	11.48
Prince George's	MD	4	Pennsylvania Avenue	0.52	9.79
Prince George's	MD	200	Intercounty Connector	0.00	2.96
Prince George's	MD	295	B/W Parkway	0.00	12.36
Prince George's	US	50	John Hanson Mem. Parkway	0.00	14.39	Same as I-595
Queen Anne's	US	50 & 301	Blue Star Mem. Highway	0.00	11.82
Queen Anne's	US	301	Blue Star Mem. Highway NB	32.40	39.49
Washington	US	40	National Pike	0.00	17.53
Washington	US	340	Jefferson Pike	1.56	2.27
Wicomico	US	13	Salisbury Bypass/ S Fruitland Blvd	0.55	11.83
Wicomico	US	50	Salisbury Bypass/ Ocean Gateway	12.48	19.06
Worcester	MD	90	Ocean City Expressway	0.00	11.83

Cities of Regional Importance

This is a work in progress as of December 2021.

City	County	Population (2020)	Note
Cumberland	Allegany	20859	County Seat
Frostburg	Allegany	9002
Keyser, WV	Allegany	4864
Annapolis	Anne Arundel	40812	County Seat
Cockeysville	Baltimore	24184
Baltimore	Baltimore City	585708	County Seat
Reisterstown	Baltimore	26822
Towson	Baltimore	59553	County Seat
Prince Frederick	Calvert	3226	County Seat
Rehoboth Beach, DE	Caroline	1108
Denton	Caroline	4848	County Seat
Westminster	Carroll		County Seat
Hampstead	Carroll
Sykesville	Carroll
Hanover, PA	Carroll
Rising Sun	Cecil
Northeast	Cecil
Elkton	Cecil		County Seat
Newark, DE	Cecil
Middletown, DE	Cecil
La Plata	Charles		County Seat
Cambridge	Dorchester		County Seat
Frederick	Frederick		County Seat
Oakland	Garrett		County Seat
Uniontown, PA	Garrett		Regional
Grantsville	Garrett
Elkins, WV	Garrett		Regional
Somerset, PA	Garrett		Regional
Bel Air	Harford		County Seat
Edgewood	Harford
Aberdeen	Harford
Havre de Grace	Harford
Ellicott City	Howard		County Seat
Chestertown	Kent		County Seat
Washington, DC	Montgomery
Rockville	Montgomery		County Seat
Gaithersburg	Montgomery
Upper Marlboro	Prince George's		County Seat
Dover, DE	Queen Annes
Centreville	Queen Annes		County Seat
Stevensville	Queen Annes
Leonardtown	St. Mary's		County Seat
Princess Anne	Somerset		County Seat
Crisfield	Somerset
Easton	Talbot		County Seat
Hancock	Washington
Hagerstown	Washington		County Seat
Frederick	Washington
Charlestown, WV	Washington
Gettysburg, PA	Washington
Salisbury	Wicomico		County Seat
Fenwick Island, DE	Worcester
Pocomoke City	Worcester
Ocean City	Worcester
Snow Hill	Worcester		County Seat

Cities with over 10,000 population

Cities 10K+	2020 census
Baltimore	585,708
Frederick	78,171
Rockville	67,117
Gaithersburg	69,657
Bowie	58,329
Hagerstown	43,527
Annapolis	40,812
College Park	34,740
Salisbury	33,050
Laurel	30,060
Greenbelt	24,921
Cumberland	19,076
Westminster	20,126
Hyattsville	21,187
Takoma Park	17,629
Easton	17,101
Elkton	15,807
Aberdeen	16,254
Havre de Grace	14,807
Cambridge	13,096
New Carrollton	13,715

Places with over 20,000 population

Places 20K+	2020 census
Columbia	104,681
Germantown	91,249
Silver Spring	81,015
Waldorf	81,410
Glen Burnie	72,891
Ellicott City	75,947
Dundalk	67,796
Wheaton-Glenmont	68,860
Bethesda	68,056
Towson	59,553
Aspen Hill	51,063
Bel Air South	57,648
Potomac	47,018
Severn	57,118
North Bethesda	50,094
Catonsville	44,701
Essex	40,505
Woodlawn	40,469
Severna Park	39,933
Odenton	42,947
Clinton	38,760
Oxon Hill-Glassmanor	37,221
Olney	37,221
Chillum	36,039
Randallstown	33,655
Montgomery Village	34,893
Suitland-Silver Hill	32,220
Pikesville	34,168
Parkville	31,812
Owings Mills	35,674
Bel Air North	31,841
Eldersburg	32,582
Carney	29,363
Milford Mill	30,622
Perry Hall	29,409
Crofton	29,641
South Laurel	29,602
Reisterstown	26,822
Edgewood	25,713
Lochearn	25,511
Middle River	33,203
North Potomac	23,790
Scaggsville	9,217
Pasadena	32,979
Fort Washington	24,261
Fairland	25,396
Ilchester	26,824
Arnold	24,064
Landover	25,998
Cockeysville	24,184
Arbutus	21,655
White Oak	16,347
Elkridge	25,171
North Laurel	25,379