CHAPTER THREE MOBILITY FOR ALL Transportation and land use interact in a criti- - Connect neighborhoods and community fea- cal way to determine the quality of life in the tures together. Yankton Plan. In any community, the trans- - Create a balanced system that also includes portation system fills many functions - as a life- non-automobile modes, including pedestrian, line for business and industry, a tool for eco- bicycle, and public transportation. nomic self-sufficiency and human dignity, a form-giver to the city, and an amenity and vi- tal service for residents. GOALS This chapter recommends a transportation system that supports the concepts of land use and city development presented in Chapter Two. In sup- porting the land use concept and providing for the needs of regional movement, Yankton’s transpor- tation system must: - Address functional issues that result from Yankton’s position in the regional transporta- tion system; - Provide enhanced movement around the city; and 53 Mobility For All ANALYSIS PATTERNS OF MOBILITY This section examines important elements of the transportation system that will assist in develop- ing specific projects and policies. It discusses the structure of the city’s street system and the role that its individual parts play. A Place in the Region Yankton’s pattern of land use and supporting transportation systems should: Yankton is served by a regional highway system that gives it a central regional role, and also affects • Provide for the safe and convenient movement local transportation planning. The city is situated of all residents of Yankton. at the crossroads of two major regional routes: • Assure that the transportation system is ad- - US Highway 81, a major north-south cross-coun- equate to meet the demand placed upon it. try highway that is part of a system that ulti- mately connects the Mexican and Canadian bor- • Use the transportation network to support de- ders. To the north, Highway 81 connects to Inter- sirable patterns of community development. state 29 near Watertown, while to the south, it joins Interstate 135/35 near Salina, Kansas. As • Provide mobility for people who are not using such, the segment from Watertown to Salina fills automobiles. the gap between two major freeways and will gradually evolve to expressway status. Major • Encourage a balanced growth pattern that dis- segments of Highway 81 in Kansas and Nebraska tributes traffic in ways that safeguards the city’s (including the segment from Columbus to Nor- transportation system. folk, Nebraska) have already been upgraded to four-lane divided expressway facilities. In Yankton, major projects affecting Highway 81 include the planned construction of a new Mis- souri River Bridge to replace the historic Merid- ian Bridge, and the reconstruction of Broadway. - South Dakota Highway 50, providing a direct link to Interstate 29 by way of Vermillion. High- way 50 is a four-lane facility between Yankton and I-29, and includes a bypass around the city of Vermillion. West of Yankton, Highway 50 is a 54 ... Chapter Three Patterns of Mobility The Structure of the Local Street System Yankton’s street system grows from the surveyor’s grid of section lines and the natural barriers cre- ated by the Missouri River and Marne Creek and the man-made barrier of the railroad. The Mis- souri River floodplain and the river bluffs that form the south edge of the valley interrupt this regular grid to the south. The former Chicago, Milwaukee, and St. Paul Railroad enters the city from the east along Highway 50, continues parallel to 8th Street, and then continues to the northwest, also inter- rupts the traditional grid. Within the city itself, the regional connector that roughly parallels the Mis- meandering Marne Creek also has had a signifi- souri River and interchanges with Interstate 90 cant effect on the street pattern. East of Broadway, near Chamberlain. north-south streets typically bridge the creek, main- taining the continuity of the pattern. However, as Yankton is also served by secondary highways, the creek turns northwest and north on the west including: side of Broadway, the number of crossings declined. - South Dakota Highway 52, providing access to In common with patterns of many cities, later ad- the Lewis and Clark Lake/Gavins Point Dam ditions to the original grid provide reduced street area, and linking to Highway 37 and the new continuity, the result of incremental development Missouri River bridge near Niobrara, Nebraska. patterns and the use of cul-de-sac streets, some of which are relatively long. This evolving pattern - South Dakota Highway 314, a short diagonal link tends to focus more traffic on section line and half- between Highways 50 and 52 west of Yankton. section line arterial and collector streets, empha- sizing a hierarchy of streets in place of the former From a regional transportation perspective, continuous network. This changing pattern is Yankton is effectively a “T” intersection of major particularly evident in the northern part of the city. routes. Highway 50 becomes a strategic stem, link- ing the Interstate 29 corridor with the evolving north-south trade route comprised of I-29 north of Watertown, US 81 between Watertown and Salina, and I-135/I-35 south of Salina to the Mexican bor- der. Chapter Three ... 55 Mobility For All Street Classification gestion and traffic hazards may arise when arteri- als serve both regional/high speed traffic move- The Existing Street Classification Map, Map 3.1, ments and local service requirements, conditions displays the city’s existing federal functional clas- that are present in Yankton. Congestion and safety sification system. A street segment must be desig- problems emerge when major arterials also are nated part of the Federal Aid system to be eligible called upon to move local trips, such as trips to for Federal funding assistance for major improve- shopping facilities. To some degree, compromises ments. in traffic flow, including a slowing of traffic, should be accepted as part of the interaction between roads Streets are placed into four functional categories: and towns. In Yankton, studies indicate that, to date, a large percentage of regional traffic is in fact • Expressways: Expressways provide restricted ac- using Yankton as an endpoint, further reducing cess, free-flow roads, designed to carry high traffic the problem of conflicts. When conflicts become volumes at high speeds with minimum friction. unsustainable, alternative solutions, such as high- All traffic movement is lane-separated by flow di- way bypasses or alternative routes, may become rection, and all intersections with local and re- advisable. gional roads are made with grade-separated inter- changes. Highway 50 meets expressway standards • Minor Arterials: These major streets connect with as it leaves the Yankton jurisdiction. and complement the major arterial system by link- ing major activity centers and connecting various • Principal Arterials: These roads serve regional parts of the city together. Unlike expressways, mi- needs and connect major activity centers. They nor arterials usually provide access to adjacent usually serve the highest traffic corridors and in properties and generally accommodate extensive some cases are designed to accommodate relatively left-turn movements and curb cuts. These major high speeds, typically with multi-lane facilities. streets are designed for speeds of 40 mph or below. Since principal arterials through the city also are As a rule, these streets are spaced at 0.5 to 1.0 mile major regional routes, they also may experience in developed urban areas and 2.0 miles in fringe significant truck traffic. Principal arterials often areas. Minor arterials in Yankton include: use access control devices such as raised medians to reduce traffic conflicts, and are subject to access - 2nd Street (Highway 50 to Walnut) control regulations that limit intermediate curb - 3rd Street (Mulberry to Broadway) cuts. - 4th Street (Broadway to Summit) - 8th Street (Highway 50 to Broadway and Summit Highways 81 (Walnut, 2nd and Broadway Streets), to West City Limits Road) and Highway 50 (4th Street, Broadway and 31st - 15th Street (Ferdig to West City Limits Road) Streets) through Yankton are classified as princi- - 21st Street (Peninah to West City Limits Road) pal arterials. In addition to their roles as regional - Whitting Drive (east city limits to 8th Street) arterials, these streets are also Yankton’s major lo- - Ferdig Avenue (8th to 15th) cal traffic carriers, and include major concentra- - Peninah Street (8th to 21st) tions of commercial uses. Potential issues of con- - Burleigh Street (4th to 15th) 56 ... Chapter Three Patterns of Mobility - Mulberry Street (2nd to 4th) - Pine Street (2nd to 4th) - Capitol Street (2nd to 4th) - Douglas Street (2nd to 31st) - Walnut Street (4th to 8th) - Summit Street (4th to 21st) - West City Limits Road (8th to 31st) • Collectors: The collector system links neighbor- hoods together and connects them to arterials and activity centers. Collectors are designed for rela- tively low speeds (30 mph and below) and provide unlimited local access. Collectors run within resi- should not exceed 300 feet in length only in excep- dential areas and distribute trips from arterials to tional circumstances. Numerous cul-de-sacs in the their ultimate destinations. They also collect traf- western part of the city often limit access to other fic from a neighborhood’s local streets and chan- parts of the city. nel it to arterials. Examples of collectors