Loading...
HomeMy WebLinkAboutTRA_StaffMemo_Apr11TRAFFIC REVIEW ADVISORY BOARD AGENDA ITEMS APRIL 2011 OLD BUSINESS 1. REQUEST FOR 4-HOUR PARKING ON BOTH SIDES OF FAIRFAX DRIVE FROM PHEASANT CREEK DRIVE TO 110 FEET EAST OF PHEASANT CREEK DRIVE. (CURRENT CONDITION: UNRESTRICTED PARKING.) This is a citizen request. Analysis Presented at March 2011 Meeting The citizen making this request is concerned over unwanted vehicles being parked in front of his property. The citizen claims that the vehicles remain on the street most of the time, and are moved primarily to comply with the City’s overnight parking requirements. He is concerned with the aesthetic concerns of these vehicles, as well as with safety during the winter months when the roadway width might be narrower. This particular request would preserve on-street parking, but would regulate its duration so that on-street parking is available more for short-term parking than for longer-term vehicle storage. Requests for parking restrictions on local streets are typically evaluated first on the basis of safety-related concerns, and second on the basis of neighborhood concerns. From a safety perspective, if the street width is less than 17 feet, parking is to be prohibited on both sides of the street; if the width is 17 to 24 feet, parking is to be prohibited on one side of the street. Parking restrictions may also be appropriate if any of the following are true: Traffic volumes are relatively high for a local street (i.e. 1,000 or more vehicles per day) There is adequate parking availability (i.e. less than 50 percent utilization of available on-street parking) There are sight distance challenges, such as curves, hills or obstructions Fairfax Drive has a street width of 32 feet, so parking restrictions are not necessary. Traffic volumes on Fairfax Drive at its intersection with Pheasant Creek Drive are about 300 vehicles per day. In the daytime hours, there appears to be adequate availability of on-street parking. Sight distance near the intersection is adequate. Hence, it would not be appropriate to recommend parking restrictions from a safety perspective. From a neighborhood perspective, parking restrictions may be appropriate when the street width is 25 to 33 feet and there is a valid petition from neighbors advocating the restriction. In the absence of a formal petition, staff has typically sent notices of Board meetings to adjacent property owners, so that they may express their support or opposition for requests like these. I do not believe this request to restrict parking is necessary from a traffic safety perspective. It may be appropriate to consider this restriction based on the sentiment of the neighborhood. Summary of Previous Meeting Discussion This item was laid over from the March meeting since Board members felt that other alternatives might provide a better solution to the one presented on the agenda. Based on input from citizens, it was suggested that parking be prohibited on one side of the road, in order to prohibit the ability of people to park overnight. In addition, it was suggested extending the no parking area so that it would continue southeast through the curve on Fairfax Avenue. To consider this, a motion to amend the request would need to be approved by the Board. To reflect the discussion, the request would need to be amended to state the following: A request for no parking on the southwest side of Fairfax Avenue from Pheasant Creek Drive to 350 feet southeast of Pheasant Creek Drive. For clarity, the distance of 350 feet is along the centerline of the road, and carries the parking restriction to the boundary between 1225 Fairfax Avenue and 1235 Fairfax Avenue. NEW BUSINESS 2. A REQUEST FOR A TRAFFIC SIGNAL AT THE INTERSECTION OF WESTFIELD STREET AND WITZEL AVENUE. (CURRENT CONDITION: WITZEL AVENUE IS A THROUGH STREET.) This is a citizen request. The closure of 9th Avenue for reconstruction this year has increased the amount of traffic using Witzel Avenue crossing Highway 41, and has likely resulted in an increase in traffic on Witzel Avenue at its intersection with Westfield Street. Traffic volumes on Witzel Avenue are expected to be elevated during this year’s construction season, as well as next year when the STH 21 interchange is under reconstruction. The citizen making the request wanted to see a temporary signal at this intersection, similar to the one installed at Westhaven Drive and 9th Avenue in 2010. The Transportation Department uses traffic signal warrants from the Manual on Uniform Traffic Control Devices to provide an objective, consistent and proven way of assessing whether the benefits of a signal might outweigh the costs. The following is the staff’s preliminary analysis of these warrants. Warrant 1: Eight-Hour Vehicular Volume. This warrant is based on having a sufficient traffic volume on both streets at a given intersection over a minimum of eight hours of the day. Table 1 summarizes traffic volumes at this intersection as collected in April 2008. Table 1: Hourly Traffic Volumes at Westfield Street and Witzel Avenue, April 2008  Satisfying this warrant would require: a) eight hours each day of 600 vehicles per hour on Witzel Avenue and 200 vehicles per hour on Westfield Street; b) eight hours each day of 900 vehicles per hour on Witzel Avenue and 100 vehicles per hour on Westfield Street; or c) 80 percent of the volume necessary to meet condition a) and 80 percent of the volume necessary to meet condition b). Condition b) appears to be satisfied, but only the right-turning traffic is no more than 20 percent of the Westfield Street traffic. While formal counts have not been conducted, previous observations have not indicated that left-turning traffic is such a dominant movement at this intersection. Warrant 2: 4-Hour Vehicular Traffic Volume. This warrant is also based on large volumes of intersecting traffic, and looks at hourly traffic during any four hours of a given day. To satisfy this warrant, there must be four points above the curve shown in Figure 1. As was true with Warrant 1, this warrant would be satisfied so long as only a small portion (~25 percent) of Westfield Street traffic is turning right.  Figure 1: Evaluation of Warrant 2, Westfield Street and Witzel Avenue, April 2008 Warrant 3: Peak Hour. This signal warrant is intended for use at a location where traffic conditions are such that for a minimum of 1 hour of an average day, the minor-street traffic suffers undue delay when entering or crossing the major street. According to the MUTCD, “This signal warrant shall be applied only in unusual cases, such as office complexes, manufacturing plants, industrial complexes, or high-occupancy vehicle facilities that attract or discharge large numbers of vehicles over a short time.” As such, this warrant is not applicable in this case. Warrant 4: Pedestrian Volumes. This warrant requires minimum pedestrian volumes during a peak hour or over a four-hour period, as well as a lack of gaps in traffic in which pedestrians may safely cross. The requirement is for there to be 190 pedestrians crossing in a single hour or 100 pedestrians in each of four hours during a day. While pedestrian data were not collected, it is doubtful that such pedestrian volumes are occurring on a regular basis. Warrant 5: School Crossing. This warrant is a variant of the previous warrant and focuses on pedestrian crossings toward a school. As this intersection is not in close proximity to a school, this warrant is not applicable. Warrant 6: Coordinated Signal System. This warrant can be used to help traffic progression through signals by preserving platooning of vehicles. Given the distance from adjacent traffic signals, this warrant is not applicable. Warrant 7: Crash Experience. Traffic signals can be used to improve intersection safety. The following must be satisfied: Five or more reported accidents of types susceptible to correction by a traffic signal within a twelve month period; the volume of traffic is at least 80 percent of the required level for the minimum vehicular volumes from Warrant 1; and adequate trial of alternatives with satisfactory observance and enforcement has failed to reduce the crash frequency. Table 2 summarizes the crash history at this intersection from 2006 to date. Table 2: Number of Crashes at Westfield Street and Witzel Avenue, 2006-2010  Of the 12 crashes observed in the three-year period from 2008 to 2010, six involved a southbound left-turning vehicle striking a westbound vehicle. In most cases, the southbound vehicle failed to see westbound vehicles in the inside lane around vehicles in the curb lane. This type of accident could be eliminated through the use of a signal; however, the frequency of these accidents does not rise to the level to satisfy this warrant. Warrant 8 – Roadway Network. A traffic signal may be installed to encourage concentration and organization of traffic flow on a roadway network, especially in the intersection of two major streets. Witzel Avenue is an arterial and Westfield Street is a collector street, so this intersection could meet the definition of two major streets. According to this warrant, “The need for a traffic control signal shall be considered if an engineering study finds that the common intersection of two or more major routes meets one or both of the following criteria: A. The intersection has a total existing, or immediately projected, entering volume of at least 1,000 vehicles per hour during the peak hour of a typical weekday and has 5-year projected traffic volumes, based on an engineering study, that meet one or more of Warrants 1, 2, and 3 during an average weekday; or B. The intersection has a total existing or immediately projected entering volume of at least 1,000 vehicles per hour for each of any 5 hours of a non-normal business day (Saturday or Sunday).” While the peak-hour traffic volume easily meets the requirement under criterion A, the 5-year projected volumes would only exceed Warrants 1, 2 or 3 if right-turn movements are a minor portion of the Westfield Street traffic. Warrant 9: Intersection near a Grade Crossing. The purpose of this relatively new warrant is to look at special circumstances where the intersection’s proximity to a railroad grade crossing is the main reason for considering a signal. With no rail line near this intersection, this warrant is not satisfied. This intersection was last analyzed for a traffic signal in July 2005. While some warrants appeared to be satisfied at that time, staff recommended against a signal for the following reasons: The signal would increase delay on westbound Witzel Avenue during peak periods. Much of the Westfield Street traffic relates to Oshkosh West High School, which has several other routes available with traffic signals. Right-turning traffic is likely a significant component of Westfield Street traffic.(A turning analysis was not conducted at that time.) The crash rate was low. At that time, the Board voted against recommending a signal. Since that time, traffic volumes on Witzel Avenue have increased, while volumes on Westfield Street appear to have decreased slightly. This would increase the potential delay associated with a signal compared to what would have occurred in 2005. Crash rates continue to be relatively low. While the intersection may potentially satisfy a signal warrant, I believe that a right-turn analysis will likely conclude that no signal warrants are satisfied. If the Board wishes, this request can be deferred to a future meeting until this analysis can be conducted. Otherwise, I recommend denial of this request. 3. A RECOMMENDATION FOR A PROTECTED LEFT-TURN FOR WESTBOUND WITZEL AVENUE TO SOUTHBOUND SAWYER STREET. (CURRENT CONDITION: PERMITTED LEFT.) This is a citizen request. The citizen making this request is concerned that construction-related detours, such as the forthcoming reconstruction of Knapp Street, may increase the number of westbound left-turning vehicles at this intersection. These vehicles currently have a permitted left turn movement, where they must wait for an acceptable gap before making their turn. The citizen is concerned that the increased left-turn volume could result in unacceptable delay and congestion at this intersection, especially as the various detours come into play. Currently, there is a protected eastbound left-turning phase. Because the left-turning movements share a lane with the through movements, it would not be possible to have both the eastbound and westbound left turn movements be protected at the same time. Therefore, it would be necessary to have a lead/lag timing, where one of the protected movements precedes the movement of through traffic (“lead”), while the other one follows it (“lag”). In both cases, the shared lane would require that the protected turn be provided, even if no vehicles are waiting to turn left. According to the Wisconsin Department of Transportation Traffic Signal Design Manual, a left-turn arrow is recommended based on a combination of the amount of left-turning traffic and the amount of oncoming traffic. Specifically, using the notations in Figure 2, the following equation must be true during the peak hour: a ( (b + c) ( 100,000  Figure 2: Peak Hour Traffic Volumes at Sawyer Street and Witzel Avenue Traffic volume data were collected during an afternoon peak period in April 2009. According to these traffic volumes, the equation listed before is not satisfied. To satisfy this warrant, the left-turn volume would need to increase by over 500 percent due to construction-related traffic detours. It is reasonable to expect an increase in traffic during construction, however it is likely that some traffic which would normally use Knapp Street will instead use Ohio Street and 9th Avenue to avoid the 4-way stop controlled intersection at Sawyer Street and 5th Avenue. This intersection was analyzed using our traffic analysis software to see what impact this might have on delay at the intersection. The results of this analysis for PM peak hour traffic volumes are shown in Table 3. The table shows the average delay per vehicle (in seconds) for each approach to the intersection, along with the corresponding level of service (LOS). LOS is a qualitative measure that helps to assess the relative quality of traffic operations. The level of service is assigned on an A through F scale, with A signifying free flow conditions, and F signifying a breakdown in flow. Typically, the goal is to attain a level of service of D or better. Table 3: Estimated Average Delay (in seconds) and Level of Service (LOS) at the Intersection of Sawyer Street and Witzel Avenue (PM Peak Period)  Due to the low volume of westbound left-turning traffic, this request does not appreciably change delay for westbound traffic. However, delay for eastbound traffic is increased considerably, since there is a reduction in the amount of time available for left-turning and through movements. Overall, the request would appear to increase delay at this intersection. It should be noted that this analysis is based on normal (i.e. non-construction) traffic volumes. However, the proposed traffic signal timing change would still significantly increase delay for eastbound traffic, so that it is unlikely to improve delay at this intersection. This request would be more likely to yield delay benefits if there were a dedicated left turn lane. Then, detection could be installed to ensure that the left-turn phase is activated only when vehicles are waiting to turn left. However, this type of lane configuration cannot be accommodated within the existing intersection footprint without reducing the capacity for through traffic. In summary, the traffic volumes do not satisfy the warrant for a separate left-turn phase, and the request would likely increase delay at this intersection. I recommend denial of this request. 4. A REQUEST FOR AN ALL-WAY STOP AT THE INTERSECTION OF ALGOMA BOULEVARD AND VINE AVENUE. (CURRENT CONDITION: ALGOMA BOULEVARD IS A THROUGH STREET.) This is a citizen request. The citizen making this request is concerned that distracted and speeding drivers may make this intersection, which is near UWO and Read School, unsafe for pedestrians. The following guidelines are used for assessing whether an all-way stop sign is appropriate. Safety warrant: Five or more reported crashes in a 12-month period that are susceptible to correction by an all-way stop installation. These crashes include right- and left-turn collisions as well as right-angle collisions. Traffic volume warrant: Traffic exceeds 300 vehicles per hour for at least eight (8) hours for the major street approaches, and Traffic exceeds 200 vehicles per hour for at least eight (8) hours on the minor street approaches. Traffic volumes are relatively equal in distribution. Table 4 summarizes crash data at this intersection from 2006-2010. As can be seen, there is a relatively small number of crashes at this intersection, which means that an all-way stop sign is not warranted on the basis of safety. Sight distances are relatively good at this intersection, and the fact that Algoma Boulevard is a one-way street also helps to reduce the number of potential vehicle conflicts. Table 4: Number of Crashes at Algoma Boulevard and Vine Avenue, 2006-2010  Traffic volume data for this intersection were collected in October 2009, and are summarized in Table 5. As can be seen, the traffic volume on Vine Avenue exceeds 200 vehicles in only four hours of a typical weekday, and the traffic volumes between the two streets are not relatively equal in distribution. Table 5: Hourly Traffic Volumes at Algoma Boulevard and Vine Avenue, October 2009  Algoma Boulevard is currently a principal arterial, which is intended to facilitate longer trips within the urban area. From a regional mobility perspective, it is important to allow these streets to flow without stops, unless there is a compelling reason to do so. Neither the safety nor the traffic data support a need to change the traffic control at this time. I recommend denial of this request.