---
type: "Bill"
title: "IDOT-TRAFFIC STUDIES"
description: "Amends the Department of Transportation Law of the Civil Administrative Code of Illinois. Requires the Department of Transportation to conduct a traffic study following the occurrence of any crash involving a pedestrian fatality that occurs at an intersection of a federal or municipal highway."
jurisdiction: "us/states/il"
legislature: "Illinois General Assembly"
session: "104th"
identifier: "SB 1559"
citation: "Illinois SB 1559 (104th)"
classification: ["bill"]
subjects: []
status: "enacted"
primary_sponsors: ["Ann M. Williams", "Sara Feigenholtz"]
version_count: 5
action_count: 45
vote_count: 6
first_action: "2025-02-04"
last_action: "2025-08-01"
source: "openstates"
source_identifier: "ocd-bill/f6bd18c4-889e-46bf-859b-fb297e8b4763"
source_url: "https://ilga.gov/Legislation/BillStatus?DocNum=1559&GAID=18&DocTypeID=SB&LegId=160263&SessionID=114"
source_hash: "7c2948fd4907df1324302c0e724a7d652b79a4d69ceb6e69e0ceb5caca310d69"
vintage: "2026-07-01"
source_snapshot: "https://data.openstates.org/daily/2026-07-01/public.pgdump"
retrieved_at: "2026-07-06"
confidence: "reported"
tags: ["legislation", "bill", "us-il"]
---

# Illinois SB 1559 (104th) — IDOT-TRAFFIC STUDIES

Amends the Department of Transportation Law of the Civil Administrative Code of Illinois. Requires the Department of Transportation to conduct a traffic study following the occurrence of any crash involving a pedestrian fatality that occurs at an intersection of a federal or municipal highway.

## Version chain

The bill's text revisions, in order — the diff chain from filing to enrollment.

1. **Introduced** (filed) — [source](https://ilga.gov/documents/legislation/104/SB/PDF/10400SB1559.pdf)
2. **Engrossed** (committee substitute) — [source](https://ilga.gov/documents/legislation/104/SB/PDF/10400SB1559eng.pdf)
3. **Senate Amendment 001** (committee substitute) — [source](https://ilga.gov/documents/legislation/104/SB/PDF/10400SB1559sam001.pdf)
4. **Senate Amendment 002** (committee substitute) — [source](https://ilga.gov/documents/legislation/104/SB/PDF/10400SB1559sam002.pdf)
5. **Enrolled** (enrolled) — [source](https://ilga.gov/documents/legislation/104/SB/PDF/10400SB1559enr.pdf)

## Votes

- Transportation — **15–0** (pass) · upper
- Transportation, Amendment 2 — **19–0** (pass) · upper
- Transportation — **15–0** (pass) · upper
- Third Reading — **52–0** (pass) · upper
- Transportation: Vehicles & Safety — **12–0** (pass) · lower
- Third Reading — **111–0** (pass) · lower

## Sponsors

- Ann M. Williams — primary (person)
- Sara Feigenholtz — primary (person)
- Anne Stava — cosponsor (person)
- Bradley Fritts — cosponsor (person)
- Jaime M. Andrade, Jr. — cosponsor (person)
- Kelly M. Cassidy — cosponsor (person)
- Margaret Croke — cosponsor (person)
- Martha Deuter — cosponsor (person)
- Matt Hanson — cosponsor (person)
- Michael J. Coffey, Jr. — cosponsor (person)
- Theresa Mah — cosponsor (person)
- Wayne A. Rosenthal — cosponsor (person)
- Will Guzzardi — cosponsor (person)

## Timeline

The legislative action history — every referral, reading, and vote.

- **2025-02-04** Filed with Secretary by Sen. Sara Feigenholtz `filing`
- **2025-02-04** First Reading `reading-1`
- **2025-02-04** Referred to Assignments
- **2025-02-11** Assigned to Transportation `referral-committee`
- **2025-03-05** Postponed - Transportation
- **2025-03-14** Senate Committee Amendment No. 1 Filed with Secretary by Sen. Sara Feigenholtz `amendment-introduction`
- **2025-03-14** Senate Committee Amendment No. 1 Referred to Assignments
- **2025-03-18** Senate Committee Amendment No. 1 Assignments Refers to Transportation
- **2025-03-18** Senate Committee Amendment No. 1 Adopted `amendment-passage`
- **2025-03-19** Do Pass as Amended Transportation; 015-000-000
- **2025-03-19** Placed on Calendar Order of 2nd Reading March 20, 2025 `reading-2`
- **2025-04-03** Senate Floor Amendment No. 2 Filed with Secretary by Sen. Sara Feigenholtz `amendment-introduction`
- **2025-04-03** Senate Floor Amendment No. 2 Referred to Assignments
- **2025-04-08** Senate Floor Amendment No. 2 Assignments Refers to Transportation
- **2025-04-08** Senate Floor Amendment No. 2 Recommend Do Adopt Transportation; 019-000-000
- **2025-04-10** Second Reading `reading-2`
- **2025-04-10** Senate Floor Amendment No. 2 Adopted; Feigenholtz `amendment-passage`
- **2025-04-10** Placed on Calendar Order of 3rd Reading April 11, 2025
- **2025-04-11** Third Reading - Passed; 052-000-000 `passage, reading-3`
- **2025-04-11** Arrived in House `introduction`
- **2025-04-11** Chief House Sponsor Rep. Ann M. Williams
- **2025-04-11** First Reading `reading-1`
- **2025-04-11** Referred to Rules Committee
- **2025-04-17** Assigned to Transportation: Vehicles & Safety `referral-committee`
- **2025-04-30** Do Pass / Short Debate Transportation: Vehicles & Safety; 012-000-000
- **2025-04-30** Placed on Calendar 2nd Reading - Short Debate `reading-2`
- **2025-04-30** Added Alternate Chief Co-Sponsor Rep. Jaime M. Andrade, Jr.
- **2025-04-30** Added Alternate Chief Co-Sponsor Rep. Matt Hanson
- **2025-04-30** Added Alternate Chief Co-Sponsor Rep. Margaret Croke
- **2025-04-30** Added Alternate Chief Co-Sponsor Rep. Bradley Fritts
- **2025-05-08** Added Alternate Co-Sponsor Rep. Martha Deuter
- **2025-05-09** Added Alternate Co-Sponsor Rep. Will Guzzardi
- **2025-05-09** Added Alternate Co-Sponsor Rep. Theresa Mah
- **2025-05-09** Added Alternate Co-Sponsor Rep. Michael J. Coffey, Jr.
- **2025-05-09** Added Alternate Co-Sponsor Rep. Wayne A. Rosenthal
- **2025-05-16** Second Reading - Short Debate `reading-2`
- **2025-05-16** Placed on Calendar Order of 3rd Reading - Short Debate
- **2025-05-20** Added Alternate Co-Sponsor Rep. Anne Stava
- **2025-05-21** Third Reading - Short Debate - Passed 111-000-000 `passage, reading-3`
- **2025-05-21** Passed Both Houses
- **2025-05-21** Added Alternate Co-Sponsor Rep. Kelly M. Cassidy
- **2025-06-18** Sent to the Governor `executive-receipt`
- **2025-08-01** Governor Approved `executive-signature`
- **2025-08-01** Effective Date January 1, 2026
- **2025-08-01** Public Act . . . . . . . . . 104-0110 `became-law`

## Source

OpenStates / OpenCivicData bulk snapshot [2026-07-01](https://data.openstates.org/daily/2026-07-01/public.pgdump); origin `ocd-bill/f6bd18c4-889e-46bf-859b-fb297e8b4763`. Confidence: reported (aggregated from official Illinois legislature records).