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Click images to view a larger version I-95 between downtown Miami and I-595 near Fort Lauderdale is one of the most heavily traveled portions of urban interstate highway in America. Weekday traffic volumes between the Golden Glades Interchange and S.R. 112 reach as high as 300,000 vehicles per day, resulting in high levels of congestion in morning and afternoon peak hours. Figure ES-1 shows the corridor covered by the analysis. Between I-595 to the north and the Golden Glades Interchange in northern Miami-Dade County, the project would involve simple conversion of existing single-HOV lanes in each direction to high-occupancy toll (HOT) operation. South of the Golden Glades Interchange, six different project configurations and operational scenarios were tested as part of the alternatives analysis. These ranged from simple conversion of existing HOV lanes to HOT to deployment of reversible HOT lanes to construction of an elevated roadway with up to four lanes of additional high-speed traffic. Managed lanes involve the creation and preservation of a portion of total capacity which would be generally free from congestion. Depending on operating scenario, the managed lanes may be open toll-free to high-occupant vehicles, while non-HOVs would be permitted to use the lanes for a toll charge. Tolls would not be charged on existing toll-free general purpose lanes. All tolls would be collected electronically, and demand and congestion in the managed lanes would be managed by raising or lowering toll rates depending on time and direction of travel. Study OverviewThe study included the development of a detailed operations profile, including quantification of average travel speeds and bottleneck areas. Extensive surveys were undertaken, including both origin-destination and extensive stated preference surveys. These surveys provide useful information regarding values of time and propensity to use the toll lanes from among travelers currently using I-95. Several focus groups were also undertaken to gauge citizen reaction to the proposed managed lane concept. A detailed economic review was also completed culminating in the development of updated socioeconomic forecasts and new trip tables for use in the analysis. Three levels of models were developed to analyze the different alternatives:
Six different project options were analyzed in the study. This included development of preliminary traffic and revenue estimates, optimum tolls and impacts on operating conditions along the corridor. After review of these, FDOT selected two alternatives as the most promising. These were then subjected to a refined traffic and revenue analysis, culminating in forecasts of annual net revenue. Current ConditionsTraffic volumes along portions of I-95 are extremely high, reaching as much as 300,000 per typical weekday. The entire section of the corridor between S.R. 112 and the Golden Glades Interchange has average weekday volumes of 290,000 or more. North of the Golden Glades Interchange, average daily traffic ranges from 192,000 to 285,000, just south of the I-595 Interchange. Essentially, this entire portion of I-95 includes eight general purpose lanes, four in each direction, plus two HOV lanes, one in each direction. Vehicles with two or more occupants are currently allowed to use HOV lanes during peak periods. Traffic is heavily constrained during peak periods and even during midday hours volumes decline only marginally from their peak levels. Morning peak hour speeds were found to be as low as 21.3 MPH in speed and delay runs conducted in 2005. Afternoon peak congested speeds averaged 27.6 MPH during peak hours. Focus groups were conducted early in the study to assess I-95 traveler reactions to the potential managed lanes. Almost 200 people participated in different groups. A majority of single-occupant vehicle operators and transit participants like the idea of managed lanes, while HOV users were less positive. However, 76 percent of both SOV and HOV participants acknowledged they would use the managed lanes at least occasionally, with at least 20 percent saying they would use them all the time. Only 11 percent of the focus group participants said they expected to never use the managed lanes because they did not want to pay tolls. Preferred AlternativesEach of the six alternatives was subjected to preliminary analysis under two alternative operating assumptions:
This carpool definition was found to significantly influence traffic and revenue potential. Based on the preliminary analysis, it was clear that some of the options would not be operationally viable unless the definition of carpool was changed from two to three. Vehicles with two or more occupants simply make up a significantly high proportion of total traffic that essentially fill the managed lanes under certain scenarios leaving little or no room to sell to non-HOV traffic. The preliminary analysis also showed that the directional imbalance over most sections of I-95 was not sufficient to support full reversible managed lane operations. Scenarios which would simply convert two single directional HOV lanes to reversible operations were found to negatively impact operations on I-95 by taking away an HOV lane in the minor travel direction while demand necessitated this additional capacity. The study also found that directionality is opposite at the northern end of the corridor, in Broward County, and the southern portion of the corridor, south of the Golden Glades Interchange. In the morning peak hour, for example, heavy traffic is northbound in the Broward County portion of the corridor and southbound in most of the Miami-Dade County portion of the corridor. Based on the results of the alternatives analysis, FDOT selected two alternatives as most promising. These included Alternatives 5 and 6. As shown in Figure ES-2, Alternative 5 would involve the simple conversion of existing HOV lanes to HOT operation north of the Golden Glades Interchange. South of the interchange, a three-lane elevated roadway would be constructed. The elevated roadway would operate as express toll lanes and all traffic using these lanes would be required to pay a toll. Existing HOV lanes at current roadway level would be retained for carpool traffic. A moveable barrier would be provided on the elevated roadway to permit two lanes to be operated in the major travel direction and one lane in the minor direction.
As shown in Figure ES-3, Alternative 6 would be similar to Alternative 5 except the elevated roadway would have a full four-lane cross section. Two lanes would be operated in each direction at all times and a fixed median barrier would be provided. Once again, the existing HOV lanes, and all four general purpose lanes in each direction would be retained south of the Golden Glades Interchange. Under either alternative, tolls would be collected using SUNPASS electronic toll collection only. Electronic toll gantries would be constructed at several locations along the project corridor. In the single-lane sections of the project, separate lanes would be provided in electronic toll zones to distinguish between toll-free carpool and toll paying non-carpool traffic. Variable tolls would be used, with highest toll rates assessed during peak travel periods. The project was analyzed assuming tolls would vary by distance traveled, with a per mile rate assigned for each hour of the day for each travel direction. In 2010, the assumed opening year of the project, morning peak-hour toll rates were estimated at $0.40 per mile in the southbound direction under both project alternatives and $0.45 and $0.40 per mile in the northbound direction under Alternatives 5 and 6, respectively. Rates as low as $0.15 per mile were used in midday and other off-peak hours. Optimum toll rates were based on those which would produce maximum revenue potential while still ensuring free-flow conditions in the managed lanes. As congestion would grow in future years, optimum toll rates would also increase in future analysis years, such as 2020 and 2030. 
Estimated Traffic and RevenueThe managed lanes were estimated to serve as much as 38,000 vehicles per typical weekday along the elevated roadway section, generally in the vicinity of 103rd Street, in 2010 under Alternative 5. This would increase to as much as 49,000 vehicles per weekday by 2020 and beyond. Weekday traffic estimates in the single-lane northern portion of the project reached as much as 22,000 toll paying vehicles per day, in addition to toll-free vehicles with three or more occupants under Alternative 5. Slightly higher volumes were found under Alternative 6, although more capacity would be provided under this option. In general, traffic on the elevated section of the project was constrained based on relatively high toll rates which were needed to manage demand on the single lane portions of the project. Table ES-1 shows estimated net revenues for Alternative 5. Annual toll revenues have been adjusted to reflect ramp-up over the first three years of operation. They have been further adjusted to reflect inflation, nominally assumed at 2.5 percent per year from 2005 on. Annual toll revenue under Alternative 5 would be expected to increase from $17.7 million in 2010 to $77.6 million in 2020 and $130.3 million in 2030. Operations and maintenance costs associated with toll collection only would be expected to increase from just under $5 million in the opening year to just under $10 million by 2030. This would result in annual net revenue ranging from $12.8 million in 2010 to $120.9 million by 2030. Table ES-2 shows estimated annual net revenue for Alternative 6. This scenario is found to have slightly higher toll revenue potential and slightly lower operating costs. The lower operating cost was due to the elimination of the need for management of reversible operations of the elevated roadway section. Annual toll revenue under Alternative 6 would increase from just under $20 million in 2010 to more than $137 million by 2030. Net revenue would increase from about $15 million in 2010 to $129 million by 2030.
SummaryIn conclusion, this comprehensive traffic and revenue study showed that managed lanes can have a significant positive impact on meeting future traffic growth and reducing congestion levels on this heavily used segment of urban interstate. Among other conclusions, the study showed:
I-95 is a critical north-south freeway serving Miami-Dade, Broward and other counties along the east coast of Florida. The route extends from a southern terminus at U.S. Route 1 in Miami north as far as the Canadian border, and is one of the most heavily traveled corridors in America. Within South Florida, it provides an important backbone for commuter and recreational traffic, with traffic volumes exceeding 200,000 vehicles per day in many locations. Nonetheless, congestion has continued to worsen, consistent with trends in major urban areas throughout the U.S. It is increasingly difficult to widen roadways such as I-95 due to right-of-way constraints, environmental and other factors. With minimal opportunity for future widening of I-95 in Miami-Dade and Broward Counties, the Florida Department of Transportation (FDOT) submitted an application to the FHWA Value Pricing Pilot Program for a comprehensive traffic and revenue study of possible managed lanes along portions of I-95. That study was approved and a team headed by Wilbur Smith Associates (WSA) was selected to undertake the study in mid-2004. Study ObjectiveThe objective of the study was to make a comprehensive examination of traffic and revenue potential of proposed managed lanes on I-95, generally between Fort Lauderdale and Miami, under a variety of physical and operational alternatives. The study was performed at a level of detail consistent with that expected for a study intended for use in project financing. However, in this case, more detailed PD&E studies will be needed in advance, hence ultimate project financing is probably some time away. The study included an extensive program of market research, including focus groups, stated preference surveys and a limited travel pattern survey. A detailed operations profile was developed for the I-95 corridor since motorists’ willingness to pay tolls to use managed lanes is dependent on operating conditions in the adjacent toll-free general purpose lanes. Six project alternatives were analyzed, using a corridor “micro-model,” and operations simulation model. From the six primary alternatives, two preferred options were selected and refined estimates of traffic and revenue potential were developed. Project corridorAs shown in Figure 1-1, the proposed managed lanes were evaluated in a corridor on I-95 extending from just south of I-595 in Fort Lauderdale to just south of the I-95 junction with S.R. 836 and I-395, near downtown Miami. This covers a total length of 18.4 miles, about 12 miles of which would be located in Miami-Dade County and the remainder in Broward County. Along this stretch, I-95 carries well over 200,000 vehicles per day, with weekday traffic approaching 300,000 on several sections. Heaviest traffic is generally immediately south of the Golden Glades Interchange; the junction of Florida’s Turnpike, I-95 and the Palmetto Expressway (S.R. 826). Immediately north of the Golden Glades Interchange traffic is somewhat lower on I-95 but increases again to more than 275,000 vehicles per day south of I-595.
For the most part, as shown in Figure 1-2, this section of I-95 includes a total of ten travel lanes, five in each direction. Four of these lanes in each direction are full-time general purpose lanes, while the leftmost lane in each direction is reserved for high-occupant vehicles, currently defined as vehicles with two or more occupants, during peak periods. An HOV treatment is used, which permits continuous access and egress to the HOV lanes and full general purpose use during off-peak hours and on weekends.
In the Broward County portion of the corridor, directional demands are relatively balanced during the morning and afternoon peak period and may slightly favor the northbound direction in the A.M. peak close to Fort Lauderdale. In the southern portions of the project, in Miami-Dade County, there is a slightly greater directional split, favoring the southbound direction in the morning peak and the northbound in the afternoon peak. However, there are very high levels of demand in the off-peak direction as well, in both counties. The existing HOV lanes operate continuously over the entire length of the study corridor. An HOV bypass elevated section has been constructed through the Golden Glades Interchange. Currently, the HOV lanes end at S.R. 112 on the south, with a direct connection to and from the west on S.R. 112. There are no HOV lanes in the short section between S.R. 112 and S.R. 836 on I-95. Chapter 2 of this report presents a detailed description of current traffic levels and the traffic operational profile on I-95. While traffic is especially heavy during peak periods, high levels of traffic exist almost throughout the daylight hours, making the corridor a potentially good candidate for managed lanes or other form of tolled express lane facilities.
Scope of WorkThe comprehensive study included an extensive program of market research and outreach. This included computer based stated preference surveys, which were intended to measure motorists’ willingness to pay tolls and general propensity to use the proposed managed lanes. A series of focus groups were undertaken, targeted to represent different segments of the travel population in the I-95 corridor, to assess public opinion and general acceptability of the concept. A limited origin-destination survey was undertaken, using digital imaging of vehicle license plates, and a mailback survey technique. The survey resulted in a relatively small sample of observed travel patterns on the corridor; this was supplemented by a detailed select link analysis of the trip patterns in the regional travel demand model to get a clear understanding of travel patterns and characteristics. A detailed traffic operations profile was compiled over the entire length of the study corridor. Two permanent automatic traffic recorder stations were located in the corridor, and these provided a full array of daily, seasonal, and hourly traffic variations by travel direction. In addition, hourly ramp counts were obtained from FDOT at all interchanges, and complete peak versus off-peak operating profiles were established over the entire length of the corridor. Speed and delay runs were operated, using GPS technology, along I-95 at various times of day to measure current patterns of delay, congestion points and to provide a basis for calibration of the detailed traffic simulation models used in the study. Future-year global travel demand estimates along the I-95 corridor were developed using the Tri-County Southeastern Regional Planning Model (SERPM). Included with this model was a set of socioeconomic growth forecasts for Miami Dade, Broward County and the overall modeling area. Given the comprehensive nature of this study, WSA retained an independent economic subconsultant, Washington Economics Group, Inc. (WEG) to conduct an independent review of the underlying socioeconomic forecast. Some minor revisions were made in the socioeconomic estimates and new trip tables developed for use in the analysis. A three-tiered modeling approach was used. The SERPM model was used to estimate total demand in the corridor; that is the total amount of traffic demand on I-95 itself. A market share “micro-model” was developed, using a tight “window” of the SERPM model, to estimate the share of traffic between the toll-free general purpose and the tolled managed lanes for each project configuration. A third model was a VISSIM micro-simulation program to estimate changes in travel speeds and travel times under varying shares of traffic between the toll-free and tolled managed lanes. Six project alternatives were evaluated ranging from simple conversion of the existing HOV lanes to HOT operation, to a possible multi-lane elevated roadway to be constructed south of the Golden Glades Interchange. A more detailed description of each option is provided later in this chapter. After the initial traffic and revenue analysis for all six options, two preferred alternatives were identified. Refined traffic and revenue estimates were developed for these alternatives and are presented later in this full report. A limited number of sensitivity tests were performed, such as reduced growth or alternative values of time, to estimate the potential impact of changes in certain basic study assumptions. Finally, the work was documented in a series of interim submittals, including WSA and subconsultant reports and technical memoranda, and finally compiled into this report. Description of AlternativesAs noted above, six alternative configurations were fully evaluated in the study. These are briefly described below. Alternative 1As shown in Figure 1-3, Alternative 1 would involve simply converting the existing single HOV lanes in each direction to HOT operation from I-595 on the north to S.R. 112 on the south. The lanes would be operated in their current locations, but for purposes of this analysis, it was assumed that they would be converted to HOT operations 24 hours per day. In addition, there would be limited points of access and egress, unlike the open access system in use with the HOV lanes today. Specific access point assumptions for each alternative are described subsequently. South of S.R. 112, new HOV lanes would be constructed through the I-195 and I-395 Interchanges. This would likely take the form of elevated HOT lanes over this relatively short distance. The new section of elevated lanes would be operated in the same way as the remaining portions of the HOT lanes. As noted above, this alternative was considered under two operating scenarios, one assuming HOV was defined as two or more persons, while the second option defined as HOV with having three or more occupants. This has a significant impact on operational viability, since there are considerably less three-occupant vehicles in the traffic stream than two-occupant vehicles. In fact, the study found that if the definition of HOV is not increased above two occupants, there will be little or no capacity available in the HOV lane to sell to non-HOV traffic; hence, this alternative may not be practical under the HOV-2 scenario. 
Figure 1-3
Conceptual Project Configuration – Alternative 1 Alternative 2As shown in Figure 1-4, Alternative 2, north of the Golden Glades Interchange, would be identical to Alternative 1. In fact, for the most part, all six scenarios were assumed to be the same north of the Golden Glades Interchange; that is two single HOT lanes, one in each direction, with controlled points of access. South of the Golden Glades Interchange, the two HOT lanes would be converted to reversible operation, with two lanes operating southbound in the morning peak and the two lanes operating northbound in the afternoon peak. Under this scenario, there would be no HOV or HOT lane provided in the minor travel direction during peak hours or in either direction during off-peak hours. Similar to Alternative 1, the HOT lanes would be extended south of S.R. 112 and into the northern periphery of downtown Miami, presumably on an elevated section. This section, too, would include two reversible lanes operated northbound or southbound during the different peak periods. 
Figure 1-4
Conceptual Project Configuration – Alternative 2 Alternative 3Figure 1-5 shows the proposed configuration for Alternative 3. Again, north of the Golden Glades Interchange, only a single HOT lane in each direction would be operated. South of the Golden Glades Interchange, a third lane would be added in the median, together with a moveable barrier wall. This would permit two HOT lanes operating in the major direction and one major HOT lane operating in the minor direction. Figure 1-5 shows a typical morning peak condition, with two lanes operating southbound and one operating northbound. This would be reversed in the afternoon peak. South of S.R. 112, an elevated extension of the lanes was assumed, also to be three lanes, the center lane of which would be reversible. This alternative has the advantage of providing additional HOT lane capacity in the major direction, while not taking away any capacity in the minor direction or during off-peak hours. 
Figure 1-5
Conceptual Project Configuration – Alternative 3 Alternative 4As shown in Figure 1-6, Alternative 4 would feature construction of a new elevated roadway south of the Golden Glades Interchange. In this case, the new lanes would be in addition to the existing two HOV lanes on the lower roadway. Hence, the existing 10-lane cross section would be retained, with the leftmost lanes reserved for HOV operation, at least during peak periods. The elevated lanes, which are assumed to be reversible in Alternative 4, would be tolled express lanes. All vehicles using these lanes would be required to pay a toll, regardless of vehicle occupancy. However, carpools could still continue to use toll-free the existing HOV lanes south of the Golden Glades Interchange. North of the Golden Glades Interchange, Alternative 4 would operate the same as all alternatives; a single HOT lane in each direction as far north as I-595. The elevated roadway would extend into downtown Miami, with fixed points of access between the express lane roadway and the general purpose lanes. For purposes of analysis, it was assumed that the toll-free HOV lanes would also be extended south of S.R. 112, into the northern edge of downtown Miami. 
Figure 1-6
Conceptual Project Configuration – Alternative 4 Alternative 5Figure 1-7 shows the hypothetical proposed configuration for Alternative 5. This is the same as Alternative 4, except that the elevated roadway would be constructed with three lanes, two operating in the major direction and one operating in the minor direction. Again, all traffic using the elevated roadway would be required to pay a toll, regardless of occupancy. However, the existing toll-free HOV lanes located on the existing general roadway would remain available for carpool traffic. 
Figure 1-7
Conceptual Project Configuration – Alternative 5 Alternative 6As shown in Figure 1-8, Alternative 6 would be identical to Alternative 5, except that the elevated roadway would be constructed with a total of four lanes, two in each direction. A fixed barrier would be provided on the elevated roadway, together with fixed points of transition between the tolled express lanes and the general purpose lanes at various locations between the Golden Glades Interchange and downtown Miami. Where the express lanes were constructed, the HOV lanes would also remain available, toll free for carpools and buses. North of the Golden Glades Interchange, the same two HOT lanes would be operated, as with all project alternatives.
Access AssumptionsFigure 1-9 shows the proposed HOT/express lanes access assumptions for each project alternative. As noted above, the northern portion of the project would be identical under all six of the operational alternatives. In this section, single HOV lanes would be converted to HOT operation, with one lane operating in each direction. Fixed points of access and egress would be constructed immediately south of I-595, between Sheraton Street and Hollywood Boulevard and between Ives Dairy Road and Miami Gardens Drive. Fixed access and egress slip ramps, probably delineated simply with striping, would be provided at these locations. The lower portion of Figure 1-9 shows access assumptions for the southern part of the proposed project. Different access assumptions were used for different project alternatives, as shown. 
Figure 1-9
Proposed HOT/Express Lanes Access Assumptions by Project Alternative Alternative 2 would involve reconstruction of the HOV lanes south of Florida’s Turnpike to reversible HOT operation. This scenario would also include the southerly extension to I-395 and beyond. In this case, it would be necessary to add intermediate access points in the vicinity of Florida’s Turnpike, since the lanes north of Florida’s Turnpike would not be reversible. This additional access would provide access to and from the reversible lanes and bi-directional lanes. Order of PresentationChapter 2 provides a description of the existing operating traffic profile along I-95 within the project limits. Chapter 3 summarizes the corridor growth potential and the results of the independent economic review. A summary of the market research program, included the stated preference surveys and focus group results, is provided in Chapter 4. Preliminary traffic and revenue estimates for the various project alternatives are summarized in Chapter 5 while more detailed information for the preferred options are presented in Chapter 6, together with sensitivity test results. The evaluation of traffic and revenue potential for managed lanes such as those proposed for I-95 requires the development of a detailed traffic and operations profile. Motorists’ willingness to pay a toll to use managed lanes, or HOT lanes, is, of course, dependent on levels of congestion in the competing toll-free general purpose lanes. Hence, it is important to consider not only daily traffic levels but also hourly traffic distributions, directional splits and vehicle composition. This chapter presents a summary of the detailed traffic and operations profile developed for I-95 for use in this study. It includes an analysis of daily and hourly traffic variations, vehicle occupancy rates, a general assessment of travel patterns and characteristics and historical traffic trends. In addition, extensive speed-delay runs were made during peak, off-peak and shoulder hour conditions along I-95; a summary of this is also included.
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Table 2-1
Average Annual Percent Change: |
Historical traffic trends are shown in Table 2-1 for a location south of Pembroke Road. FDOT operates a continuous count station at this location, which shows that average daily traffic increased from 205,600 in 1995 to 252,000 in 2005, an average annual increase over the 10-year period of 2.1 percent. Annual traffic growth has been relatively stable over the 10 years, with year-to-year fluctuation but five-year average growths virtually the same between 1995 and 2005.
The nominal 2 percent average annual rate of traffic growth in Broward County is considered typical of the overall corridor. This rate of growth is lower than some other facilities in the region, likely due to the fact that traffic volumes are already exceptionally high and congestion routinely occurs, especially south of the Golden Glades Interchange.
Hourly traffic variations are shown in Figure 2-3 at two locations along I-95; south of Pembroke Road and south of 151st Street. Hourly traffic is shown for a typical weekday condition, separately by northbound and southbound directions.
At the northern location (south of Pembroke Road) in Broward County, peak hour traffic in both directions is relatively balanced, with slightly heavier southbound volumes in some hours, but only by a small margin. Peak hour volumes reach about 8,600, per direction, close to the capacity of I-95 at that location, which includes four general purpose and one HOV lane in each direction.
It is interesting to note, however, that hourly demands decrease only a small amount during shoulder and even mid-day hours. In fact, in the southbound direction, all hours between 7:00 A.M. and 6:00 P.M. were found to be in the range of 7,500 to 8,600 vehicles per hour.
At the Miami-Dade County selected location, south of 151st Street, slightly more directional peaking is shown, with slightly heavier volumes southbound in the morning peak and northbound in the afternoon peak. Total hourly traffic flows are also slightly higher, with peak direction/peak hour volumes reaching as much as 9,600 vehicles per hour, at or above the nominal capacity of this section of road.
Once again, traffic in the southbound direction shows relatively small variations between hours of the day. Northbound traffic does show a late morning dip prior to a steady increase in traffic during the afternoon hours.
Perhaps most important to note is the lack of pronounced directional splits at either of these locations. Some of the options studied for the managed lanes included use of reversible or variable lanes, northbound versus southbound. The relatively small directional imbalances may tend to make these options less effective.
Figures 2-4 and 2-5 show A.M. and P.M. peak period traffic profiles along all mainline sections and ramps of I-95 within the project limits. Hourly volumes are shown by direction at all locations. Figure 2-4 shows A.M. peak period (6:00-9:00 A.M. - 3 hours) traffic volumes along I-95. As noted above, directional imbalances are relatively small, but would favor the southbound direction in the A.M. peak period south of the Golden Glades Interchange. Interestingly, within Broward County the major direction is northbound in the A.M. peak period, although relatively small directional imbalances are shown.
This is another important finding of the study, inasmuch as the north and south ends of the proposed managed lanes would have opposite directional peaking characteristics. This further complicates potential pricing strategies needed to manage demand along the full length of the facility and add further question regarding the viability of reversible lanes. It is noted that none of the six alternatives studied included reversible lanes in the Broward County portion of the project.
Figure 2-5 provides the P.M. traffic profile, again at 2004 levels. This covers the three-hour P.M. peak period from 3:00 – 6:00 P.M. In this case, directional flows are slightly higher in the northbound direction, south of the Golden Glades Interchange, and relatively balanced in the Broward County section. Three-hour volumes currently reach 27,000 – 29,000 in some locations, reflecting an average of 9,000 – 10,000 vehicles per hour per direction. These are exceptionally high traffic levels, and are indicative of the levels of congestion which were found in extensive speed studies performed as part of the analysis.
Figure 2-6 presents the profile information on a single hour basis for A.M. peak, mid-day and P.M. peak conditions. Northbound and southbound traffic volumes are shown in separate colors. This is a convenient way of showing the distribution of peak traffic loadings over the length of the facility, while also pointing out directional splits wherever these may exist.
In the A.M. peak hour, southbound volumes south of the Golden Glades Interchange are shown to be between 9,000 and 10,000 per hour at most locations. Northbound volumes in the A.M. peak are considerably lower. The nominal capacity of the general purpose lanes in this area would be in the range of 8,000 vehicles per hour, recognizing the presence of trucks in the traffic stream. Traffic volumes above 8,000 need to be accommodated in the HOV lane; it is clearly shown that for many sections, the HOV lanes and general purpose lanes would likely be at capacity, south of the Golden Glades Interchange.
Immediately north of the Golden Glades Interchange, traffic levels drop off considerably, to as low as 5,000 vehicles per hour per direction. This is due to the significant amount of traffic which leaves I-95 for Florida’s Turnpike and Palmetto Expressway. Traffic levels build steadily moving north, with the increased commuting demand to and from Fort Lauderdale.
Similar patterns are shown in the P.M. peak hour, although slightly lower peaking levels are experienced. Also, the directional imbalance south of the Golden Glades Interchange is not as pronounced as in the A.M. peak hour. Traffic is shown to be quite balanced directionally in the Broward County section.
Hourly traffic volumes in the mid-day hours are also shown to be quite high, particularly south of the Golden Glades Interchange. Even in mid-day hours, total southbound volumes, for example, exceed 8,000 vehicles per hour on several sections. The leftmost lane is not restricted to HOV during these hours; hence the total roadway capacity is close to 10,000 per hour per direction. Nonetheless, these relatively high volumes even during mid-day hours suggest that with future traffic growth, there may well be a need for managing demand even in off-peak hours.
FDOT maintains vehicle classification counts at its continuous count stations. One of these stations is located on I-95 within the project study area, just south of Pembroke Road in Broward County. Table 2-2 shows the percent distribution between passenger cars and commercial vehicles at three points over the last 10 years.
Passenger cars, as a proportion of total vehicles, have remained relatively constant over the last 10 years, increasing from 93.4 percent in 1995 to 93.8 percent in 2003. The total commercial vehicles are generally split evenly between single and multi-unit trucks, with multi-unit trucks representing 3.2 percent in 2003 while light trucks represented 3.0 percent. In analyzing the various project alternatives, trucks were assumed to be prohibited from any of the HOT lane sections of the project alternatives, although theoretically all vehicle classes might be eligible to use the elevated lanes in Alternatives 4, 5 and 6 since separate HOV lanes are provided.
Table 2-2
Source: Florida Department of Transportation |
A limited travel pattern and characteristic survey was undertaken as part of the study. License plate images were obtained at a pedestrian overpass location south of the Golden Glades Interchange and on selected ramp locations along the corridor.
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Figure 2-7 shows the proportional distribution of license plate by zip code of vehicle registration. As might be expected, vehicle registrations are most heavily concentrated along the I-95 corridor itself, in eastern Miami Dade and Broward Counties. The heaviest concentrations were found in close proximity to the county line.
License plate surveys were also conducted at a major park-and-ride in the vicinity of the Golden Glades Interchange. Figure 2-8 shows the zip code distributions of license plates from that location; these are heavily concentrated along the eastern portion of the Broward/Miami-Dade County line, just north of the Golden Glades Interchange. That park-and-ride facility provides express bus service to and from downtown Miami; consistent with the distribution pattern of vehicle registrations.
To provide a general assessment of the relative distribution of trip patterns along this section of I-95, WSA performed a select link analysis at the northern and southern ends of the corridor, using the base year trip tables from the SERPM travel demand model. These are graphically shown in Figure 2-9.
The left side of the figure displays the distribution of trips to and from the north end of the corridor, at a select link location just south of I-595. Of trips using I-95 in Fort Lauderdale, 67 percent are traveling to or from local interchanges north of the Golden Glades Interchange. About 8 percent of the traffic is oriented to the Golden Glades Interchange itself, mostly the Palmetto Expressway, while another 8 percent is found to be using local interchanges between the Florida Turnpike and S.R. 112. About 17 percent of the trips on I-95 south of I-595 continue through the entire length of the corridor, to or from S.R. 112, S.R. 836 or points south.
The right side of the graphic shows the distribution of travel patterns from a select link location just north of S.R. 112, near the south end of the project. About 40 percent of I-95 traffic in this location comes from local interchanges between S.R. 112 and the Golden Glades Interchange. Almost one-fourth of traffic is using Florida’s Turnpike or the Palmetto Expressway, while about 36 percent is traveling to local interchanges in Broward County, or to I-595 and north. Through trips represent about 18 percent, comparable to the proportion of through trips at the northern select link location.
Vehicle occupancy levels are extremely critical to this analysis, recognizing that all of the alternatives have at least a portion of the project which will be operated as HOT lanes. As noted previously, each of the alternatives was analyzed under two operational scenarios, one assuming carpools with two or more occupants would gain toll-free access while another limited this to vehicles with three or more occupants.
Figure 2-10 shows the estimated vehicle occupancy distribution along the I-95 corridor for typical weekday conditions. Data is shown separately for northbound and southbound directions and for A.M. and P.M. peak period conditions. This data was obtained from the 2004 I-95 High Occupancy Vehicle Lane Monitoring report, produced for FDOT. The occupancy distributions were obtained at a location near NW 79th Street in Miami-Dade County. In that study, periodic counts were obtained of vehicle occupancies in both the HOV lane and immediately adjacent general purpose lane.
WSA reviewed this information and made adjustments to reflect the total volume of traffic in all four general purpose lanes. This resulted in the development of occupancy distributions across all five lanes at this location, which is shown in Figure 2-10.
As might be expected, the highest category of occupancy distribution is the single-occupant vehicle, ranging from 80.5 to 84.1 percent of total traffic. Vehicles with two occupants generally represent between 14.7 and 17.9 percent of the total. Vehicles with three or more occupants represented a very small percentage of traffic, as low as 0.9 percent in the northbound A.M. peak hour to 2.7 percent in the southbound direction.
It is important to note that vehicles with two or more occupants represent an extremely high percentage of total HOV traffic. This suggests that if the definition of carpools was increased from two to three occupants, a significant amount of additional capacity would be opened up in the HOV lanes. This is an important consideration in this study analysis.
A limited trip characteristics survey was undertaken, using a mailback approach from vehicles observed in the I-95 corridor. Figure 2-11 presents a summary of the trip purpose and trip frequency distributions which were found. These were from survey respondents, all of which were driving on I-95 during the period of the survey.
Trips to and from work was the primary peak period trip purpose, with about 74 percent of respondents indicating this. Other trip purposes were relatively evenly distributed during the peak period. About one-third of off-peak users were also commuters, although another one-third were conducting company or personal business.
In terms of trip frequency, two-thirds of peak period travelers made the trip five or more times per week. Only 15 percent were infrequent travelers. As might be expected, during off-peak hours, high frequency trips declined to 28 percent of the total, while low frequency trips (one or less per week) increased to 39 percent of the total.
