Minnesota Administrative Rules

8820.9946 MINIMUM DESIGN STANDARDS, URBAN; RECONDITIONING PROJECTS.

Subpart 1.

Two-way streets.

In the following design chart, total width is from face-to-face of curbs.

Reconditioning projects for two-way urban roadways must meet or exceed the minimum dimensions indicated in the chart.

Number of Through Lanes and Present Traffic Volume	Total Width with No Parking	Total Width with Parking on One Side	Total Width with Parking on Both Sides	Proposed Structural Design Strength
	(feet)	(feet)	(feet)	(tons)
2-Lane with ADT < 10,000	22	28	34	(b) 9
4-Lane with ADT < 10,000	44	51	58	(b) 9
2-Lane with ADT ≥ 10,000 (a)	22	28	34	9
4-Lane with ADT ≥ 10,000	44	51	58	9
6-Lane	66	(c)	(c)	9

Engineering judgment may be used to choose a lane-width or shoulder-width dimension other than the widths indicated in the chart for roadways. Factors to consider include safety, speed, population/land use, benefit/cost analysis, traffic mix, peak hourly traffic, farm equipment, environmental impacts, terrain limitations, bicycle traffic, pedestrian traffic, other nonmotorized uses, functional classification, or other factors. Widths less than those indicated in the chart require a variance in accordance with parts 8820.3300 and 8820.3400.

(a) Permissible for present traffic volumes less than 15,000 ADT.

(b) When ADT is less than 5,000, seven tons is allowable.

(c) No parking is allowed.

When a median is included in the design of the two-way roadway, a one-foot reaction distance to the median is required on either side of the median. Minimum median width is four feet.

For ADT less than 150, the widths of bridges to remain must be at least the sum of the lanes. For ADT greater than or equal to 150, the widths of bridges to remain must be at least the sum of the lanes plus half the sum of the shoulders, parking lane, and curb reaction distance. Bridges to remain must have a load rating factor of at least 0.75 using the AASHTO Manual for Bridge Evaluation, LRFR (load and resistance factor rating) for inventory level.

Subp. 2.

One-way streets.

In the following design chart, total width is from face-to-face of curbs.

Reconditioning projects for one-way urban roadways must meet or exceed the minimum dimensions indicated in the chart.

Number of Through Lanes	Present ADT	Total Width with No Parking	Total Width with Parking on One Side	Total Width with Parking on Both Sides	Proposed Structural Design Strength
		(feet)	(feet)	(feet)	(tons)
2-Lane	< 5,000	21	29	37	7
	5,000-10,000	23	31	39	9
	10,000-15,000	23	31	39	9
	≥ 15,000	24	32	40	9
3-Lane	All	34	42	50	9

For ADT less than 150, the widths of bridges to remain must be at least the sum of the lanes. For ADT greater than or equal to 150, the widths of bridges to remain must be at least the sum of the lanes plus half the sum of the shoulders, parking lane, and curb reaction distance. Bridges to remain must have a load rating factor of at least 0.75 using the AASHTO Manual for Bridge Evaluation, LRFR (load and resistance factor rating) for inventory level.

Subp. 3.

Exception.

Any street that was previously built to state-aid or state standards, or that was granted a variance to standards in effect at the time of construction or reconstruction, or that is a trunk highway turnback, but does not meet current standards, may be reconditioned regardless of subparts 1 and 2.

Statutory Authority:

MS s 14.386; 14.389; 162.02; 162.09; 162.155

History:

20 SR 1041; 23 SR 1455; 24 SR 1885; 29 SR 449; 36 SR 925; 37 SR 697; 42 SR 485

Published Electronically:

November 20, 2017