2 Del. Admin. Code § 2.6

Current through Reigster Vol. 28, No. 6, December 1, 2024

Section 2.6 - SIGNALIZED ACCESS STUDY REQUIREMENTS

When properly designed and located, traffic signals can safely and efficiently control motor vehicle, pedestrian, and bicycle traffic by assigning the right-of-way at intersections. However, poor placement and design of the traffic signal and associated intersection can lead to excessive delay and increased crash rates. The decision to install a new traffic signal is at the sole discretion of DelDOT. New traffic signals will not be considered for commercial marketing purposes. The following studies will be required to be prepared by the applicant and approved by DelDOT, prior to approval being granted for a new traffic signal:

2.6.1Traffic Signal Justification Report

If a Traffic Impact Study or Traffic Operational Analysis indicates that a traffic signal may be justified when the development opens to traffic, then the developer will be required to complete a Traffic Signal Justification Report. The report should be completed by a Delaware registered professional engineer and should include the following:

A. Analysis of existing conditions

1. Approach lane widths

2. Approach lane configurations

3. Location and lengths of exclusive turn lanes (storage and taper length should be noted separately)

4. Other geometric features

5. Horizontal and vertical geometry (description)

6. Roadside features

7. Adjacent land use

B. Collection and analysis of turning movement count data

1. 12 hours' worth of data is ideal, but 8 hours may be acceptable (include surrounding peak periods)

2. Separate cars from heavy vehicles

3. Separate counts of bicycles and pedestrians

C. Collision data

1. Obtain at least three (3) years of data to be used for the Traffic signal warrant analysis

2. This requirement may be waived at DelDOT's discretion for new intersections

D. Traffic signal warrant analysis

1. Three scenarios are typically analyzed when considering signalization related to developments:

i. Existing conditions (Is a signal warranted now?)

ii. Build out of proposed site to determine when a traffic signal would be warranted. For example, if the site was commercial, how many operational parcels would warrant a signal? For a residential site, how many lots would warrant a signal? (Multiple scenarios may be required based on the construction schedule. The analysis should reflect the construction schedule, keeping in mind the Plan Review approval process, of the site.

2. Complete build out of the site (Is a signal warranted only when the entire site is built out?)

3. All nine (9) warrants provided in the Delaware Manual on Uniform Traffic Control Devices (DE MUTCD) should be evaluated if they are applicable. Some may not be applicable to the specific location being studied.

E. Intersection Capacity Analysis

1. Evaluate the operation of the intersection based on the outcome of the traffic signal warrant analysis. If a signal is warranted, how will it operate? If not, how will it operate?

2. Evaluate queue lengths at impacted intersection and effected intersections in the surrounding area.

3. Conduct capacity analysis, typically using HCS or Synchro. If the proposed signal is in a corridor and will be coordinated with other signals, now or in the foreseeable future, cycle lengths in the analysis should match existing signal's cycle lengths.

4. Conduct a Critical Movement analysis at the impacted intersection.

5. If applicable, evaluate the impact a pedestrian crosswalk may have at the impacted intersection. A recommended location for the crosswalk(s) should be provided, considering both pedestrian path desire lines and the impact to vehicular traffic.

6. Proposed signal phasing should be noted.

2.6.2Bandwidth Analysis

If a new signal is being proposed within an existing signalized corridor, then a Bandwidth Analysis may be required. This analysis will ensure that the proposed traffic signal does not negatively impact the progression along a corridor. The analysis may result in a recommendation as to the best location to situate a new signalized intersection along the corridor. Alternately, if the locations cannot be easily adjusted, the analysis may indicate that the intersection should in fact not be signalized, or that the number of lanes required may be more than indicated by a capacity analysis alone (to ensure adequate green time for the mainline corridor).

A. When a study is required, the study shall be completed and signed by a Delaware registered professional engineer using the following standards:

1. Highway signal progression bandwidth and efficiency analysis including current and anticipated future signalized intersections. The number of signals to be included in the study shall be at DelDOT's discretion.

2. An optimum signal cycle as determined by DelDOT

3. Actual speeds as determined by a spot speed study

4. The goal is to achieve a coordinated, signalized corridor with an optimized highway bandwidth. The requirement is that the bandwidth with the proposed traffic signal be no less than the optimized existing bandwidth without the proposed traffic signal.

5. The green time allowed for the cross street shall be no less than the time necessary to accommodate pedestrian movements.

B. The study shall also provide the following information:

1. Notation of all existing access, possible future access locations within the scope of work defined by DelDOT, and all potential roadway and signal improvements

2. Current and future arterial travel speed, travel time, and delay time

3. Traffic generation rate estimates

4. Information, data and reference sources

5. An evaluation of the level of service for all geometric elements

6. Accurate and understandable diagrams

7. All assumptions and adjustment factors

8. An analysis of all reasonable alternatives including a no build alternative

9. A conceptual design showing all geometric elements and approximate dimensions with detailed analysis of any elements below code standards

Additional information and additional analysis based upon other factors and standards may be required if determined to be necessary for a complete evaluation.

2 Del. Admin. Code § 2.6

13 DE Reg. 1101 (02/01/10)
15 DE Reg. 551 (10/01/11)
16 DE Reg. 1199 (5/1/2013)
18 DE Reg. 240 (9/1/2014)
18 DE Reg. 709 (3/1/2015)
19 DE Reg. 938 (4/1/2016) (Final)