Kasold Preliminary Design Report

Bartlett & West Engineers was selected in May 2004 by the City of Lawrence to provide surveying and engineering services for the design of Kasold Drive from 15^th Street to Clinton Parkway. As a part of these services, a preliminary study report was completed to review several options for completing the project. This report highlights four of the many options that were considered.

Kasold Drive is an arterial street in west Lawrence that carries approximately 20,000 vehicles per day. The future traffic projections indicate that there will be 31,000 vehicles per day in 2025. The existing roadway is generally a four lane divided section, which includes a grass median. The right-of-way along the route is minimal in most areas for an arterial classification. In addition, sidewalks do no exist on either side of the road for most of the route. The route is surrounded by mostly residential properties, except for the commercial areas that exist at both ends of the project near 15^th Street and Clinton Parkway.

This stretch of Kasold Drive is characterized by several hilly areas where the vertical curves along the road are short and choppy. The vertical curves are substandard to today’s engineering criteria, and they create sight distance hazards in most locations along the route. In addition, an 11.2% street profile exists along Kasold Drive just north of Augusta Drive, which exceeds generally accepted criteria for arterial streets. The existing pavement is seriously deteriorating, and the City maintenance crews are constantly working to patch pavement areas in most locations along this stretch of Kasold Drive. Furthermore, the openings in the grass median to provide left turn movements do not provide refuge areas wide enough to protect vehicles trying to turn and get out of the way of through traffic. It is also common to see traffic stacking up beyond the provided turn lanes at the signalized intersections, especially for southbound vehicles turning from Kasold Drive onto eastbound Clinton Parkway. The bottom line is that there are a lot of obstacles along this roadway that create frequent opportunities for accidents, and this condition will only get worse as the traffic volumes continue to grow.

This stretch of Kasold Drive is surrounded by utilities. Westar Energy has an overhead main transmission and distribution line adjacent to the roadway from the south end to the north end. Aquila, SBC, and Sunflower Broadband all have facilities along the road, mostly on the west side to serve the Alvamar Estates area. Finally, the City of Lawrence has an above ground water tank at approximately 19^th Street and Kasold Drive. In addition, the City has a 12” water main from 15^th Street to Clinton Parkway, mostly under the existing pavement and median. The City also has a 6” line in the median from the water tower sight south to Augusta Drive. The relocation of the utilities will be an important part to the overall success of this project. The utilities will need to be coordinated early in the design process to ensure that their facilities are appropriately relocated prior to the commencement of the road construction.

The preliminary design elements of this study have led to several conclusions. First, vehicles turning left along Kasold should have a dedicated left turn lane allowing the driver to move their vehicle out of the flow of traffic. Therefore, the grass medians should be removed in favor of left turn lanes for even the residential street locations. Furthermore, the traffic analysis indicates that geometric improvements need to be made at Kasold’s intersections with 15^th Street and Clinton Parkway. A right turn only lane needs to be added for northbound traffic approaching 15^th Street, and dual left turn lanes and a right turn only lane are necessary for southbound traffic approaching Clinton Parkway. Second, one of the biggest issues with Kasold Drive today is the condition of the pavement. The City of Lawrence has changed its standard pavement section dramatically since Kasold was originally constructed. The existing pavement was placed on compacted soil. The proposed pavement section will consist of either 12” of asphaltic or 10” of concrete pavement, both laid on a 4” drainable base, which is placed on 9” of treated subgrade. To further protect the section from deterioration due to moisture, edge drains will be used along each edge of the pavement. If the asphaltic pavement option is selected, then Bartlett & West recommends using concrete pavement between 15^th Street and Seminole Drive and between Augusta Drive and Clinton Parkway to protect the project from pavement issues that are common around Lawrence at intersection locations with significant stopping and starting and turning movements. Finally, pedestrian access is a key element of this project. The City of Lawrence prides itself on its facilities for pedestrians and cyclists. However, this section of Kasold presently does not have a sidewalk on either side along most of the route. All but one of the options presented in this study provide for a 10’ wide recreation path along the west side of the new roadway. This recreation path will connect the recreation paths along Clinton Parkway and Kasold Drive south of Clinton Parkway to the sidewalks along 15^th Street and Kasold Drive north of 15^th Street. These connections will help the City of Lawrence to continue to upgrade the access it provides its citizens and visitors.

Four options are presented in this study. The first option is to remove and replace the existing pavement, which will minimize the overall construction costs while still improving the driving surface. The disadvantages heavily outweigh the benefits to this option. The second, third, and fourth options are all based on a new street profile that will improve the road for the traveling public and pedestrians. The second option is a complete road reconstruction with a new recreation path on the west side. The grades are largely improved and the benefits of this option certainly outweigh the disadvantages. The third option is almost identical to the second option except for that the street profile north of Augusta Drive is slightly flatter. Generally, a flatter slope would be attractive, however this leads to many problems in this area of the project. Significantly more retaining wall will be required due to the flatter profile. These additional retaining walls will have a negative affect on sight distances for residents trying to get out of their homes on the east side of Kasold Drive. The benefits still outweigh the negatives on this third option. Finally, the fourth option considers using the second option’s profile, but reducing the project limits to 15^th Street to West 22^nd Street. Like the first option, this is being considered to reduce construction costs. This option has all the benefits of the second option, except that the intersection and street grade improvements near the Clinton Parkway intersection are not completed. These intersection improvements are critical to the overall success of the project. Therefore, the fourth option is less desirable than the second or third option.

A key element to this study is the construction sequencing and schedule. It is desirable to have the project complete by the end of 2005 and our sequencing plan is based on this premise. The proposed sequencing plan will close Kasold Drive for a 10-14 week timeframe to reconstruct the north leg of the intersection of Kasold Drive and Clinton Parkway and the south leg of the intersection of Kasold Drive and 15^th Street. After these intersections are reconstructed, the remaining portion of the project will be constructed one half at a time. This will allow traffic to be carried through construction for the majority of the project. The schedule of the project will be largely impacted by the relocation of utilities. The utility companies will have to be a part of the planning process from the very beginning of the final design phase. The more time they have to react and relocate the better the likelihood is that the project will be complete by the end of 2005. Overall, the completion date is a very aggressive timeframe, but can be accomplished if the utilities are allowed to get started soon and the weather cooperates throughout the year. Any delay in the relocation of the utilities may result in the inability to complete the project in 2005.

Finally, the recommendation portion of the study provides a couple tools to manage all the pieces of this complex project. There are several individual questions that have been asked along the way, including which pavement type to use, the number of lanes necessary, etc. The matrix provided in the recommendation section assists with trying to consider all factors of the project and weighting them to provide an overall score. The recommendation section concludes with the recommendation to proceed with the second option presented in the study. While the second option is not the cheapest option, it is also not the most expensive. In addition, the second option provides the most common sense approach to balancing all the wants and needs of the project into a manageable and sensible solution.

EXISTING CONDITIONS

Kasold Drive between 15^th Street and Clinton Parkway is a four lane arterial roadway that presently carries about 20,000 vehicles per day. Traffic projections indicate that there will be 30,000 vehicles per day in the year 2025. This portion of Kasold Drive was constructed in the early 1970’s.

The existing roadway can be characterized as a four lane road section with a divided grass median throughout most of the project. There are median openings at all of the side roads to allow for access into local residential and commercial areas. Left turn only lanes are provided only at the signalized intersections, but not at any of the unsignalized intersections, other than West 22^nd Street.

This section of Kasold Drive is surrounded by three types of land uses. First, there are residential properties along both sides of the route. More specifically, residential uses are prevalent between West 22^nd Street and Seminole Drive on the west side and between West 22^nd Terrace and just north of Scioto Drive on the east side. For the most part, this is mostly single family housing, other than a few duplex units on the west side near Seminole Drive and the Quail Creek Apartment complex between Augusta and West 22^nd Street on the west side. Second, commercial areas exist at each end of the project. At Clinton Parkway, the Hy-Vee Shopping Center exists at the northwest corner of Clinton Parkway and Kasold Drive. The Hy-Vee shopping extends from Clinton Parkway to West 22^nd Street. The shopping center includes the grocery store, a bank, a restaurant, and an associated strip center with a variety of retail stores. At the southwest corner of 15^th Street and Kasold Drive, there are offices in place, included a Coldwell Banker Real Estate Office and another office building. Finally, the third entity is the ground owned by the KU Endowment Association. Presently, this is undeveloped ground that is located on the east side of Kasold Drive between 15^th Street to a point just north of Scioto Drive.

This stretch of roadway is one mile in length and there are six side roads and twelve individual properties that have direct access to Kasold. The following table shows the details for each of the side roads that intersect Kasold throughout the project length.

Existing Right-of-Way/Easements

The original Kasold Drive road record was dedicated in 1904. Since that time, additional right-of-way has been acquired at different times throughout the life of Kasold Drive. Presently, the existing right-of-way varies throughout the project limits.

Beginning at the south end of the project, the right-of-way varies drastically between Clinton Parkway and West 22^nd Street. At Clinton Parkway, the right-of-way is approximately 192.5’ in width. The right-of-way varies to a point just north of West 22^nd Street, where the right-of-way becomes 50’ each side of the section line, which is coincidental with the centerline of the roadway.

The right-of-way line on the west side remains at 50’ from the section line (centerline) from West 22^nd Street to Scioto Drive. On the east side of Kasold Drive, the right-of-way line is 50’ in width between West 22^nd Street and a point approximately 300’ north of West 22^nd Street, at which point the right-of-way line becomes 35’ on the east side. The right-of-way line on the east side remains 35’ to a point about 100’ south of Scioto Drive, except for one location. The right-of-way in front of the Kincaid Addition is actually 60’ from the section line (centerline) due to a more recent plat.

The right-of-way on the east side remains at 50’ from a point about 100’ south of Scioto Drive to the intersection of 15^th Street & Kasold Drive, except in one area. The right-of-way on the east side of the Stoneland Court Subdivision, just north of the City water tower, is 35’. On the west side of Kasold Drive, the right-of-way line is 90 feet from the section line (centerline) from Scioto Drive to Seminole Drive. The extra right-of-way width to the west is there to accommodate the frontage road that exists along Kasold Drive from Scioto Drive to Seminole Drive.

As mentioned in the previous paragraph, the right-of-way on the east side remains at 50’ from Seminole Drive to the intersection of 15^th Street & Kasold Drive. In addition, the same 50’ wide right-of-way exists on the west side of Kasold from Seminole Drive to 15^th Street.

Utility easements exist along certain portions of the route, many of which are aligned in an east-west orientation, so they intersect the existing right-of-way at one location. There are a few easements that parallel the existing right-of-way. First, a 15’ utility/pedestrian easement exists on the west side of the Kasold Drive right-of-way between West 22^nd Street and Augusta Drive. Second, a 7.5’ utility easement parallels the west edge of the Kasold Drive right-of-way between Augusta Drive and Scioto Drive.

Further detail showing the existing right-of-way and easements is shown on Figure A, which shows the existing plan view of the project.

Geotechnical Investigation

GeoSystems/Kleinfelder, Inc. was hired to drill borings at 14 different locations along the existing route. The borings were drilled to a maximum of 11’ in depth or auger refusal, whichever occurred first. Auger refusal generally indicates that unweathered rock is present.

Generally speaking, the project can be broken into two parts when considering the findings of the borings. First, the north half of the project, north of Scioto Drive, contained rock at elevations approximately 5.5’ to 6’ deep in all locations. The materials found were pavement on top of red-brown fat clays, which all lies on top of limestone rock formations. The limestone prevented the borings from reaching the maximum depth of 11’. Second, all borings taken on the portion of the project south of Scioto Drive were taken to the 11’ maximum depth. Much of the material found along the south half of the project included highly weathered shale that is characterized as soft to moderately hard. GeoSystems indicated that this material should be able to be excavated using traditional excavation techniques without the need for hammering or blasting. In addition, some areas of the south portion of the project were described as fat clays.

Somewhat surprisingly, no ground water was found in any of the borings during a time of 2004 that was pretty wet. The City of Lawrence and adjacent residents both have witnessed ground water in this area. Some residents have even indicated that springs exist in the area of the project. While no ground water was found at the boring locations, the project pavement section will provide a subsurface drainage system to handle seasonal ground water.

The 14 borings are shown on the plan and profile sheets. In addition, a full copy of the geotechnical report can be found in the appendices.

Utilities

Power, telephone, cable television, gas, and water lines exist along much of Kasold Drive between 15^th Street and Clinton Parkway. The one main utility that is not located next to this stretch of the roadway is sanitary sewer. Bartlett & West Engineers located the utilities as marked by Kansas One Call and the City of Lawrence Department of Utilities locator services and this information is provided on the plan and profile sheets presented in this report.

Each utility company was sent a set of drawings that showed the existing surveyed location for their surface and underground infrastructure. Bartlett & West asked each utility to review the drawings and provide feedback concerning their present locations. A list of utility contacts is included in the appendices. Pertinent information regarding each individual utility is discussed in more detail below.

Westar Energy

Westar Energy is prominent along Kasold Drive. There are main transmission and distribution lines located on overhead power poles and distribution lines located underground along parts of the route. Westar also provides street lighting on overhead power lines located in the grass median throughout much of the route.

The power poles and overhead power lines that carry transmission and distribution lines exist along the east side of the project from Clinton Parkway to a point just north of Tam O’Shanter Drive. The poles and lines then cross over the roadway and remain on the west side of Kasold Drive from north of Tam O’Shanter Drive to 15^th Street. This facility is of utmost concern due to the costs involved to relocate the poles and lines.

Bartlett & West, Westar Energy, and the City of Lawrence have met regarding the existing power facilities. The intent of the proposed project is to allow the overhead power lines to remain as they exist for as much of the route as possible. Westar has agreed that they will provide clearances from the existing ground line to the sag points of the overhead lines for any areas of concern once the final profile is accepted. There will most likely be between two and four poles that will have to be relocated to accommodate the new road section.

The overhead transmission and distribution lines were in place prior to the road right-of-way being expanded. Therefore, any costs required to rise, lower, or relocate those facilities will have to be borne by the City of Lawrence as a part of this project.

Aquila Inc.

Aquila has a 4” gas main that exists along the entire route. The gas line is a steel line that is well east of the project limits from Clinton Parkway to West 22^nd Terrace. Just north of west 22^nd Terrace, the gas line heads to the east for 60’ +/- and then turns north under the existing Kasold Drive. The section of gas line between West 22^nd Street and Augusta Drive was relocated a few years ago due to a local development project. This portion of the gas line is PVC. Around Augusta Drive, the gas line becomes steel again. On the west side of Kasold Drive, the gas line north of Augusta Drive to 15^th Street is then located west of the existing curb and gutter for the remainder of the project.

Bartlett & West visited with Chuck Hoag of Aquila about the potential relocation of their facility. Aquila indicated that they need 60 to 90 days to relocate the facility. Bartlett & West will need to submit the final profile to them before their engineer can begin design of the new facility.

Sunflower Broadband

Sunflower Broadband provides cable television, internet, and telephone service to customers along this route. Bartlett & West has discussed this project with Jim Day of Sunflower Broadband. Jim indicated that Sunflower’s facilities are aging in this area, and much of the existing coaxial cable is buried without a conduit. Therefore, they are welcoming the opportunity to replace their aging infrastructure with conduit encased cable lines.

Sunflower has fiber optic lines in two locations along the project. First, a fiber optic cable exists along the south side of 15^th Street and crosses Kasold Drive. Due to 15^th Street being the tie-in location for the north end of the project, it is considered unlikely that this line would be negatively impacted. Second, a fiber optic line exists on the east side of Kasold Drive between West 22^nd Terrace and a point about 150’ north of West 22^nd Street. While it does not appear likely that this line would need to be relocated, it is too early to determine for sure if that is the case. Jim indicated that if either of these fiber optic lines needed to be relocated then additional time would be necessary for their relocation.

Jim indicated that the main issue is actual location of their new fiber lines. Sunflower would entertain the notion of being located in the same trench as telephone and power. However, they do not want to be near the gas company. In addition, Jim expressed concern about where they might need to relocate. Significant grade changes create challenges with providing a new facility while keeping the existing service available. Interruption of service is not an option.

Jim felt that it would take 60 to 90 days to complete the relocation of their facility. This time frame is dependent on two main items. First, the weather would add delays to the relocation. In addition, if rock excavation is encountered then they would experience delays.

Finally, Sunflower Broadband will be responsible for all relocation costs associated with this project.

SBC

SBC has facilities along much of the route, including a fiber optic cable that runs down the middle of the existing median. Most of their facilities are buried cables along the west side of Kasold Drive. SBC has indicated that the fiber optic line that exists in the median could be taken out of service and rerouted temporarily during relocation of the existing line.

Bartlett & West met with Janice Bowers and Fred Laubach to discuss their facility. Janice and Fred verified the location of their utilities as shown on the drawings sent to them. In addition, SBC noted a few minor areas that needed to be updated, which have since been completed by Bartlett & West.

SBC indicated that they will need 6 months from the time that they receive final plans to relocate their facility. SBC will be responsible for all relocation costs associated with this project.

City of Lawrence Water

There are two City of Lawrence waterlines that exist along Kasold Drive between Clinton Parkway and 15^th Street. Both lines are approaching 40 years old.

First, there is a 12” low pressure line that extends from the north end of the project to the south end of the project. This line is located under the northbound lanes from 15^th Street to Tam O’Shanter. The 12” line jogs to the west at Tam O’Shanter and is located in the existing median from Tam O’Shanter to West 22^nd. At West 22^nd, the roadway enters two reverse curves, which moves the centerline of the road to the west. The 12” waterline continues directly south, which results in the waterline crossing under the northbound lanes. Just southeast of the intersection of Kasold Drive and West 22^nd Terrace, the waterline is located east of the existing curb line.

Second, a 6” high pressure line exists in the median from the water tower site, which is between Scioto Drive and Tam O’Shanter Drive, to Augusta Drive. The 6” waterline turns to the west at Augusta Drive to provide service for the existing residential area west of Kasold Drive.

The City of Lawrence Department of Utilities has indicated that they would prefer to relocate both of these lines outside of the new pavement limits. The early indications are that both lines would be located on the east side of the proposed Kasold Drive section. There will be limited locations where the waterline will need to remain under pavement for very short stretches. Both water lines provide services to adjacent houses. Therefore, the Utilities Department will determine how future water service will be provided to these homes.

Each utility agreed that it would be helpful to get all interested parties at a meeting soon after the final profile is adopted so that discussions can begin regarding relocation. Bartlett & West would propose holding this meeting as one of the first items to be taken care of in the final design phase. Relocating the utilities needs to be completed prior to the bidding of the project. There is some time available in Phase 1 of the construction project to allow for final work associated with the utility relocations.

PRELIMINARY DESIGN

Bartlett & West provided a traffic analysis for the existing and future traffic projects. In addition, to the traffic volume analysis, Bartlett & West reviewed accident data relating to this stretch of Kasold Drive. Based on the traffic analysis, a proposed lane configuration layout was developed. Finally, the traffic signals were analyzed to determine present and future needs.

Perhaps the most critical result of the traffic analysis is the recommendation to close the access to Kasold Drive at Scioto Drive. This analysis is discussed with the Traffic Analysis portion of the report below.

Traffic Analysi s

The existing four lane section on Kasold has two through lanes in each direction, separated by a grass median. The intersections of Kasold with: West 22^nd Street, Augusta Drive, Scioto Drive, Tam O’Shanter Drive, and Seminole Drive are all stop-controlled intersections. Currently there are median breaks on Kasold at each intersection. These median breaks do not provide any left turn storage for vehicles turning off Kasold. The absence of left turn storage increases accident potential and also slows the through traffic on Kasold, thus reducing capacity as well.

The City of Lawrence provided A.M. and P.M. peak hour turning movement counts for each of the side street intersections. These counts were used to evaluate the need for left-turn storage on Kasold. By eliminating the existing median, there is an opportunity to provide an additional turning lane at these intersections and not increase the width of the roadway. There have been engineering studies by the Federal Highway Administration, ITE and others on the use of left-turn lanes at unsignalized intersections. All studies come to the same conclusion; the addition of the left-turn reduces accidents 30% to 60%. In looking at each of the side street locations, it is necessary to provide left-turn storage on Kasold.

When considering the existing geometrics of each side road, the intersection of Scioto Drive and Kasold immediately raises safety concerns. Scioto Drive currently intersects Kasold at about a 17% grade. There is also a connecting frontage road very close to the intersection with Kasold. The existing traffic counts show that there are a total of four vehicles exiting Scioto Dr. in the morning and evening peak hours. Augusta Dr. to the south and Tam O’Shanter to the north still provide close access points to the neighborhood, so the closing of Scioto Drive would not provide any major negative influence on the local traffic using the roadway. Fire protection and emergency access would still have adequate routes to the neighborhood. In addition, both the Fire and Police Departments raised no concerns about the potential closing of Scioto Drive. The combination of low traffic volumes, poor geometrics, proximity to the adjacent frontage road, and adequate access by other routes, led us to the recommendation of closing the direct access between Scioto Drive and Kasold Drive.

If the direct access from Scioto Drive to Kasold is eliminated, there would be an opportunity to narrow the roadway section to four lanes between Augusta Dr. and Tam O’Shanter. This roadway section would be narrower than existing and provide an opportunity to minimize impacts to adjacent landowners, while trying to provide the recreation path adjacent to the proposed roadway. In narrowing the roadway to a four lane section, left-turn access would not be allowed through the southbound lanes on Kasold to the homes on the east side of the road. This access will be blocked by constructing a narrow center island to eliminate left turns in an area where no center turn lane will be available. Currently, these homes do not have left turn access due to the existing grass median. This would force a southbound vehicle to go further south, make a U-turn at the signalized intersection of West 22^nd Terrace & Kasold Drive and then back north to their residence.

Right turn lanes for southbound traffic on Kasold at W 22^nd Street and W 22^nd Terrace have been added to help maintain through traffic movement on Kasold. These lanes will be replaced as a part of the project.

Traffic Signal Analysis

Bartlett & West received both A.M. and P.M. existing peak hour turning movement counts from the City for the three signalized intersections along this project (Clinton Parkway, West 22^nd Terrace, and 15^th Street). Existing AADT (19,780 vehicles per day) and year 2025 AADT (31,000 vehicles per day) were provided be the City of Lawrence. A growth factor using the existing and future traffic volumes was determined to be 2.1%. This factor was then used to adjust all of the turning movements at the three intersections to the year 2025. This includes increasing traffic volumes on Clinton Parkway and 15^th Street at the same growth factor. The existing and future year turning movement volumes are shown below.

Trafficware Synchro 5, Traffic Signal Coordination Software was used to analyze the signalized intersections at Clinton Parkway & Kasold Drive, West 22^nd Terrace & Kasold Drive, and 15^th Street & Kasold Drive. Synchro 5 computes the capacity and Level of Service for signalized intersections in accordance with the procedures of the 2000 Highway Capacity Manual, Chapter 16. Synchro provides intersection capacity analysis and timing optimization. Synchro incorporates the SimTraffic traffic simulation model to provide traffic performance Measures of Effectiveness (MoE) beyond those provided by the HCM. These include average and maximum queue lengths, which are useful to evaluate turn lane storage requirements.

A current Level of Service was determined for each of the signalized intersections after evaluating the current intersection geometrics and traffic volumes. Year 2025 traffic projections were then inserted into the model to obtain a Level of Service of each of the intersections while maintaining the current roadway geometrics.

The two main intersections at Clinton Parkway & Kasold and 15^th Street & Kasold both currently operate in the PM peak hour at a Level of Service (LOS) C. In looking at the future year 2025 scenario, both intersections will have significant delay due to the increased traffic volume. It was our assumption that this study will look at improvements to the north leg of Kasold at Clinton and the south leg of Kasold at 15^th Street to help reduce the overall delay. The improvements identified will be a part of, and planned to work with, several improvements necessary to improve the operation of the intersections in the future.

There were several different intersection improvements that were considered along Kasold Drive.

At 15^th Street, it is necessary to add a northbound right turn lane on Kasold, as well as lengthening the existing northbound left turn bay. In order to fully separate northbound right turn vehicles, a 500’ storage length is required, or maximize the storage available prior to the Seminole Drive intersection.
At the intersection of Kasold Drive and Clinton Parkway, a southbound right turn lane was added. Dual left turn lanes were also added.

The results of the analysis of the existing, future and future with improvements are shown below. Additional Synchro model output and summaries are available upon request.

Accident Analysis

Accident history was provided by the City for the years 2001-2003. Intersection Collision Diagrams were developed for each intersection and can be provided upon request.

The un-signalized T-intersections between 15^th Street and Clinton Parkway showed an accident pattern due to the lack of left turn lanes from Kasold Drive to the side streets. Bartlett & West is proposing to provide the left turn lanes at all side roads. This should greatly reduce that accident pattern.

The intersection at 15^th Street and Kasold Drive had a total of 38 accidents in the three year period. Twenty-six of the 38 accidents were left turning vehicles colliding with opposing through vehicles. The intersection currently has protected/permissive left turns in all four directions. The northbound/southbound left turning movements meet KDOT’s warrants for protected left turn phasing. The intersection also meets the criteria for four or more accidents in one year, six or more in two years occurring on one approach. In addition, the intersection also meets the criteria for six or more accidents in one year and ten or more in two years occurring on both approaches. The collision diagram for the intersection can be provided upon request. Eliminating the permissive left turn movements from the intersection should reduce the number of accidents, but might cause increased overall delay at the intersection.

The intersection at Clinton Parkway and Kasold Drive had a total of 42 accidents in the three year period. Fourteen of these accidents were vehicles turning left off Kasold Drive to Clinton Parkway colliding with opposing vehicles. Currently this movement is protected/permissive from Kasold Drive. The installation of dual left turn lanes on the north leg of Kasold will require the north/south turning movements to be protected only. East/west left turns off Clinton Parkway are already protected. This phasing change will reduce the number of accidents at the intersection.

Although the improvements to Kasold at 15^th Street & Clinton Parkway don’t solve the overall operation problems of the intersections, they should be a part of the overall solution. The overall solution will need to include intersection improvements at the other legs of the intersection before the intersection will be considered to operate at an efficient level.

Traffic Analysis Recommendations

This project will take significant steps to increase safety along the Kasold corridor. Below is a summary of the recommendations based upon the traffic analysis, accident analysis, and signal analysis.

Close direct access from Scioto Dr. to Kasold.
Provide left turn storage on Kasold to all side roads
Provide a four lane section with a narrow median from Augusta to Tam O’Shanter
Replace southbound right turn lanes at W 22^nd Street & W 22^nd Terrace.
Provide a right turn lane and dual left turn lanes for southbound traffic on Kasold at Clinton Parkway
Provide a right turn lane for northbound traffic on Kasold at 15^th Street. Left turning phasing for northbound/southbound left turn movements on Kasold Drive at 15^th Street should be changed to protect only and the signals modified accordingly.

Finally, Figure B graphically shows the recommendations for the number of lanes at all locations along Kasold Drive between 15^th Street and Clinton Parkway. Specific transitions and lane limits will be determined during the final design phase of the project.

Pavement Design

As a part of the study Bartlett & West was responsible for examining rigid and flexible pavement systems. The purpose of examining the two pavement systems is for the design and comparison of pavement systems for the project. The pavement systems are designed for the street in accordance with the methods described in the “American Association of State Highway and Transportation Officials Guide for Design of Pavement Structures”, 1993 edition (AASHTO Guide). Several issues are involved in the pavement analysis, most of which are summarized in the following discussion. The pavement analysis report can be found in it’s entirety in the Appendices.

Design Parameters

The AASHTO Guide pavement design method requires input parameters relative to the pavement system which describe the traffic loadings that will be imposed on the system, soil conditions, concrete parameters, pavement design reliability, and pavement serviceability. The pavement design criteria were taken from the Kansas Department of Transportation and AASHTO. The analysis period for the pavement design is 30 years. Listed below are the values used for these design parameters in this report.

Traffic

Traffic loadings over the design life of the pavement are expressed as equivalent 18-kip single axle loads (ESAL). This expression is used as a common unit of measure which allows summation of different axle loads and configurations from a mixed traffic stream. This means that cars and trucks can be accounted for based on axles and then summed together.

2025 future traffic volumes, provided by the City of Lawrence, were used in the analysis. These traffic volumes and distribution are shown in the pavement analysis report in the Appendices. Assuming a linear relationship, the traffic volumes are averaged to calculate the daily two-way traffic volume for the 30 year analysis period. A directional distribution factor of 60% and a lane distribution factor of 100% are applied to the daily traffic volume.

Once the traffic volume is established, the traffic mix must be determined to assess the weights and axle loadings which will be applied to the pavement system over the analysis period. Due to the lack of statistical information in the immediate area of the proposed improvements, average distribution values were used. These values are based upon similar traffic mixes, as stated in the Kansas Department of Transportation (KDOT) study “Kansas Truck Weight Survey 1994 and 1992-1994 Combined”. Refer to the report in the Appendix for a complete listing of the traffic distribution. Average axle load equivalency factors that are also taken from the study to convert the loadings into ESALS.

Soil Conditions

Site geotechnical investigations were performed by GeoSystems/Kleinfelder in June 2004. Soil samples were taken from 14 borings extending six to ten feet below the existing ground surface drilled on the proposed project site.

The borings were monitored while drilling and after completion for the presence and level of groundwater. Groundwater was not observed in the borings. This may have been influenced by the time of year and the low permeability of the cohesive soils encountered in the borings.

Typically, the subgrade material is a fat clay material. Most of the soils encountered in the borings will have a high shrink-swell potential. Based on this typical classification, we estimate the soil design characteristics to be:

Subgrade Modulus, k, = 165 p.c.i.

Modulus of Elasticity = 4000 p.s.i.

The subgrade modulus was adjusted to account for loss of support using AASHTO Guide methods. A loss of support factor of 0.80 was used for a fly-ash treated subgrade. The resulting effective modulus of subgrade reaction is 100 p.c.i.

Fly-ash treatment of the clay subgrade soils will significantly reduce the shrink-swell potential. The City has had success on recent projects using fly-ash treated subgrades. Therefore, only fly-ash treated subgrades were looked at in this report.

Other Design Parameters

The characteristics and joint transfer information pertaining to the rigid pavement system and statistical standard deviation estimates were generally obtained from recommendations listed in the AASHTO Guide. A reliability factor of 90%, design period of 30 years, and serviceability loss of 2.5 also reflect values recommended by AASHTO Guide for urban arterials.

Pavement Systems

As a part of the pavement design, both rigid and flexible pavement systems were analyzed. The flexible system is a 2” asphaltic concrete surface course, 10” asphaltic concrete base course, a 4” bound drainable base course on a 9” fly-ash treated subgrade. All told, the flexible pavement system will be 25” thick. The rigid system analyzed includes a full-depth 10” concrete pavement with a 4” bound drainable base on a 9” fly-ash treated subgrade. Therefore, the rigid pavement system will be 23” thick.

In addition to the pavement section, edge drains will be used on both sides of the roadway to accommodate the proper drainage of subsurface ground water away from the pavement section.

Regardless of the pavement system used, the pavement will be