Draft - Memo
Date:
Project:
To:
Tuesday, November 18, 2014
I-4 SAMR Re-evaluation
Beata Styś Pałasz, PE, FDOT District Five
From
Hari Salkapuram, PE, HDR; Suraj Pamulapati, PE, HDR
Subject:
Lake Mary Blvd Interchange Alternatives Evaluation
1.0 Purpose
The Florida Department of Transportation (FDOT) has requested to evaluate interchange
alternatives for the Lake Mary Blvd interchange in the north section presented in the Interstate
4 (I-4) Systems Access Modification Report (SAMR) Re-evaluation in support of “I-4 Beyond
the Ultimate (BtU)” PD&E Reevaluation Study.
2.0 Project Location
Figure 1: Lake Mary Boulevard Interchange Location
3.0 Analysis Year
The analysis year for the alternative evaluation is the Design Year (2040).
4.0 Traffic Forecasts
This traffic analysis for the analysis year 2040 was performed based on traffic forecasts
developed as part of the I-4 SAMR Re-evaluation that is being prepared to support the I-4 BtU
PD&E Reevaluation Study. The traffic forecasts for the analysis year 2040 are included in
Attachment A.
5.0 Interchange Alternatives
Three alternatives were considered for the Lake Mary Boulevard interchange evaluation. The
list of alternatives is provided below and detailed geometry of the alternatives is provided in
Attachment B.
1. No-Build – Originally approved FHWA alternative
2. Alternative 1 – Single Point Urban Interchange (SPUI)
3. Alternative 2 – No-Build + Pedestrian Overpass across I-4+ Addt’l free NBR lane at I-4
WB Ramps intersection and exclusive 2nd EBR lane at Lake Emma Road intersection
6.0 Operational Analysis
This section discusses peak-hour operational analysis using Synchro software. The results of
the analysis and a comparison between the Alternatives are provided below.
6.1 Intersection Evaluation
A separate AM and PM peak-hour intersection analysis for study intersections was completed
in Synchro for the study intersections on Lake Mary Boulevard.
Network-wide output provides insight into the comparison between the Alternatives. Based on
the network performance comparisons, Alternative 2 provides improved operational
performance for the 2040 AM and PM peak-hour periods (Table 1).
Table 1: Lake Mary Boulevard Intersections - Measures of Effectiveness (MOEs) Comparison
AM
No-Build Alt 1 - SPUI
MOEs
Total Delay (hr)
461
520
Total Travel Time (hr)
631
925
Unserved Vehicles (#)
1042
1131
Performance Index
502
557
PM
Alt 2 Alt 2 No-Build +
No-Build +
Ped Bridge No-Build Alt 1 - SPUI Ped Bridge
348
1248
1455
1090
518
1470
1681
1313
204
4432
5654
3706
390
1299
1504
1144
Synchro Intersection Delay and LOS Summary is shown in Table 2.
Table 2: Lake Mary Boulevard Intersections – Average Delay and LOS Comparison
AM
Lake Mary
Boulevard
Intersection
with
International
Parkway
I-4 WB Ramps
I-4 EB Ramps
Lake Emma
Road/ Primera
Boulevard
MOEs
Average Delay
(sec/veh)
LOS
Average Delay
(sec/veh)
LOS
Average Delay
(sec/veh)
LOS
Average Delay
(sec/veh)
LOS
PM
Alt 2 Alt 2 No-Build + Ped
No-Build + Ped
Bridge + Addt'l
Alt 1 - Bridge + Addt'l
RT lanes
No-Build SPUI
RT lanes
No-Build
Alt 1 SPUI
56.6
E
57.6
E
58.9
E
187.8
F
179.9
F
188.3
F
43.7
D
124.2
48.4
D
39.0
D
128.2
45.7
D
108.6
F
F
55.5
E
86.8
F
F
45.9
D
101.6
F
91.5
F
79.1
E
271.1
F
283.6
F
234.4
F
6.2 Queue Analysis
The queuing results for the intersections of Lake Mary Boulevard with I-4 Ramps are
summarized in Table 3 for the analysis year 2040. The results indicate that Alternative 2
results in better queue performance for both eastbound and westbound ramps.
Table 3: Queue Analysis Summary
Off
Movement
Ramp
I-4 WB
I-4 EB
SBL
SBR
NBL
NBR
No-Build AM Alternative 1 AM
95 th %ile 95th %ile Improve
Queue
Queue
ment
738
868
-17.6%
521
267
48.8%
390
608
-55.9%
2267
2532
-11.7%
Alternative 2 AM No-Build PM Alternative 1 PM
95th %ile Improve
95th %ile 95th %ile Improve
Queue
ment
Queue
Queue
ment
768
-4.1%
674
679
-0.7%
540
-3.6%
904
613
32.2%
501
-28.5%
270
363
-34.4%
1229
45.8%
2036
2251
-10.6%
Alternative 2 PM
95th %ile Improve
Queue
ment
674
0.0%
904
0.0%
327
-21.1%
1068
47.5%
7.0 Conclusion
Based on the operational analyses of all the alternatives, Alternative 2 performs better than the
other alternatives.
8.0 Recommendation
Review of two alternatives in addition to No-Build was conducted for Lake Mary Boulevard
interchange for the analysis year 2040. Based on the operational analysis, Alternative 2
provides better operational performance among the three alternatives, ultimately improving
mobility throughout the Lake Mary Boulevard corridor. Based on the assessments and
analyses of the alternatives, Alternative 2 is recommended. However, other factors such as
costs, ROW, environmental considerations, and funding availability should be considered in
the implementation.