Under the Securities Exchange Act of 1934
(Amendment No. 1)*

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. o

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

* SEE INSTRUCTIONS.

2

* SEE INSTRUCTIONS.

3

* SEE INSTRUCTIONS.

4

* SEE INSTRUCTIONS.

5

* SEE INSTRUCTIONS.

6

* SEE INSTRUCTIONS.

7

* SEE INSTRUCTIONS.

8

* SEE INSTRUCTIONS.

9

* SEE INSTRUCTIONS.

10

* SEE INSTRUCTIONS.

11

This Amendment No. 1 hereby amends the Statement on Schedule 13D (the “Initial 13D”) previously filed on May 24, 2011 by Thayer Equity Investors V, L.P. (“Thayer”), HCI Equity Partners III, L.P. (formerly known as Thayer | Hidden Creek Partners II, L.P.) (“Partners III”), HCI Co-Investors III, L.P. (formerly known as THC Co-Investors II, L.P.) (“Co-Investors III”), TC Sargent Holdings, L.L.C. (“TC Sargent”), TC Roadrunner-Dawes Holdings, L.L.C. (“TC Roadrunner”), HC Equity Partners V, L.L.C. (“HC Equity”), TC Co-Investors V, L.L.C. (“Co-Investors”), HCI Equity Management, L.P. (“HCI”), HCI Management III, L.P. (“HCI Management III”) and HCI Equity Partners, L.L.C. (“HCI Equity Partners”) (collectively, the “Reporting Persons”) with respect to the common stock, par value $0.01 per share (the “Common Stock”), of Roadrunner Transportation Systems, Inc., a Delaware corporation (the “Issuer”) as indicated herein.  Capitalized terms used but not defined in this Amendment shall have the respective meanings ascribed to such terms in the Initial 13D.

Item 2.                                 Identity and Background.

Item 2 is amended and restated with respect to certain disclosures as follows:

The principal business address of each of the Reporting Persons is 1730 Pennsylvania Avenue, NW, Suite 525, Washington, DC, 20006.

Certain information with respect to the executive officers and directors of the Reporting Persons, if applicable, is set forth on Schedule A attached hereto.

Item 3.                                 Source and Amount of Funds or Other Consideration

Item 3 is amended and restated with respect to certain disclosures as follows:

Each of Scott D. Rued, Ivor J. Evans and Judy A. Vijums, each of whom is affiliated with one or more of the Reporting Persons, is on the board of directors of the Issuer.

Updated information regarding potential deemed beneficial ownership of Common Stock by each of Thayer, Partners III, Co-Investors III, TC Sargent and TC Roadrunner is provided under Item 5 of this Amendment No. 1.

Item 4.                                 Purpose of Transaction.

Item 4 is amended and supplemented as follows:

On May 2, 2013, Thayer sold 816,487 shares of Common Stock, TC Roadrunner sold 1,711 shares of Common Stock, TC Sargent sold 1,717 shares of Common Stock, Partners III sold 177,512 shares of Common Stock and Co-Investors III sold 2,573 shares of Common Stock.  The shares were sold in an open-market transaction to unaffiliated purchasers.

Except as set forth in Item 4, as amended and supplemented herein, and in Item 6 of the Initial 13D, as of the date hereof, the Reporting Persons do not have any plan or proposal that relates to or would result in any of the transactions discussed in sub items (a) through (j) of the instructions to Item 4.

Notwithstanding the foregoing, the Reporting Persons reserve the right to effect any such actions as any of them may deem necessary or appropriate in the future.

Item 5.                                 Interest in Securities of the Issuer.

Item 5 of the Initial 13D is amended and restated in its entirety as follows:

12

(a)                                 As of the date hereof, each of the Reporting Persons may be deemed to be the beneficial owner within the meaning of Rule 13d-3 of the Exchange Act of shares of Common Stock as described below.

(i)                                     Thayer and HC Equity may be deemed to be the beneficial owners of 13,129,922 shares of Common Stock, or approximately 35.2% of the Common Stock outstanding.  This number is comprised of: 10,815,705 shares of Common Stock held directly by Thayer, 2,224,629 shares of Common Stock issuable to Thayer pursuant to the Sargent Merger Warrant and 89,588 shares of Common Stock issuable to Thayer pursuant to the Junior Subordinated Note Warrant.

(ii)                                  Partners III may be deemed to be the beneficial owner of 2,351,435 shares of Common Stock, or approximately 6.7% of the Common Stock outstanding.  This number is comprised of shares of Common Stock held directly by Partners III.

(iii)                               Co-Investors III may be deemed to be the beneficial owner of 34,089 shares of Common Stock, or 0.1% of the Common Stock outstanding.  This number is comprised of shares of Common Stock held directly by Co-Investors III.

(iv)                              TC Sargent may be deemed to be the beneficial owner of 43,881 shares of Common Stock, or 0.1% of the Common Stock outstanding.  This number is comprised of: 22,738 shares of Common Stock held directly by TC Sargent, and 21,143 shares of Common Stock issuable to TC Sargent pursuant to the Sargent Merger Warrant.

(v)                                 TC Roadrunner may be deemed to be the beneficial owner of 22,658 shares of Common Stock, or 0.1% of the Common Stock outstanding.  This number is comprised of shares of Common Stock held directly by TC Roadrunner.

(vi)                              Co-Investors and HCI may be deemed to be the beneficial owners of 66,539 shares of Common Stock, or 0.2% of the Common Stock outstanding.  This number is comprised of the shares of Common Stock held directly by and the shares of Common Stock issuable to TC Sargent pursuant to the Sargent Merger Warrant as described in paragraph (iv) above and the shares of Common Stock held directly by TC Roadrunner as described in paragraph (v) above.

(vii)                           HCI Management III may be deemed to be the beneficial owner of 2,385,524 shares of Common Stock, or 6.8% of the Common Stock outstanding.  This number is comprised of the shares of Common Stock held directly by Partners III as described in paragraph (ii) above and the shares of Common Stock held directly by Co-Investors III as described in paragraph (iii) above.

(viii)                        HCI Equity Partners may be deemed to be the beneficial owner of 15,581,985 shares of Common Stock, or 41.7% of the Common Stock outstanding.  This number is comprised of the shares of Common Stock held directly by and issuable to Thayer pursuant to the Sargent Merger Warrant and the Junior Subordinated Notes Warrant as described in paragraph (i) above, the shares of Common Stock held directly by Partners III as described in paragraph (ii) above, the shares of Common Stock held by Co-Investors III as described in paragraph (iii) above, the shares of Common Stock held directly by and issuable to TC Sargent pursuant to the Sargent Merger Warrant as described in paragraph (iv) above, and the shares of Common Stock held directly by TC Roadrunner as described in paragraph (v) above.

13

(b)                                 Each Reporting Person may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of shares of Common Stock as described below.

(i)                                     Thayer and HC Equity may be may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of 13,129,922 shares of Common Stock, or approximately 35.2% of the Common Stock outstanding.  This number is comprised of: 10,815,705 shares of Common Stock held directly by Thayer, 2,224,629 shares of Common Stock issuable to Thayer pursuant to the Sargent Merger Warrant and 89,588 shares of Common Stock issuable to Thayer pursuant to the Junior Subordinated Note Warrant.  HC Equity’s investment committee makes investment decisions on behalf of HC Equity and may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of the foregoing shares of Common Stock.  HC Equity’s investment committee decisions are made based on the affirmative consent of HCI Equity Partners and the majority of the votes of the investment committee members, who are: Daniel M. Dickinson, Scott D. Rued, Douglas P. McCormick, Ivor J. Evans, James T. Forese and Richard Snell.

(ii)                                  Partners III may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of 2,351,435 shares of Common Stock, or approximately 6.7% of the Common Stock outstanding.  This number is comprised of shares of Common Stock held directly by Partners III.

(iii)                               Co-Investors III may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of 34,089 shares of Common Stock, or 0.1% of the Common Stock outstanding.  This number is comprised of shares of Common Stock held directly by Co-Investors III.

(iv)                              TC Sargent may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of 43,881 shares of Common Stock, or 0.1% of the Common Stock outstanding.  This number is comprised of: 22,738 shares of Common Stock held directly by TC Sargent, and 21,143 shares of Common Stock issuable to TC Sargent pursuant to the Sargent Merger Warrant.

(v)                                 TC Roadrunner may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of 22,658 shares of Common Stock, or 0.1% of the Common Stock outstanding.  This number is comprised of shares of Common Stock held directly by TC Roadrunner.

(vi)                              Co-Investors and HCI may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of 66,539 shares of Common Stock, or 0.2% of the Common Stock outstanding.  This number is comprised of the shares of Common Stock held directly by and the shares of Common Stock issuable to TC Sargent pursuant to the Sargent Merger Warrant as described in paragraph (iv) above and the shares of Common Stock held directly by TC Roadrunner as described in paragraph (v) above.

(vii)                           HCI Management III may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of 2,385,524 shares of Common Stock, or 6.8% of the Common Stock outstanding.  This number is comprised of the

14

shares of Common Stock held directly by Partners III as described in paragraph (ii) above and the shares of Common Stock held directly by Co-Investors III as described in paragraph (iii) above.  HCI Management III’s investment committee makes investment decisions on behalf of HCI Management III and may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of the foregoing shares of Common Stock.  HCI Management III’s investment committee decisions are made based on the affirmative consent of HCI Equity Partners and the majority of the investment committee members, who are: Daniel M. Dickinson, Ivor J. Evans, James T. Forese, Scott Gibaratz, Douglas P. McCormick, Daniel F. Moorse, Carl E. Nelson, Scott D. Rued, Richard Snell and Judith A. Vijums.

(viii)                        HCI Equity Partners may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of 15,581,985 shares of Common Stock, or 41.7% of the Common Stock outstanding.  This number is comprised of the shares of Common Stock held directly by and issuable to Thayer pursuant to the Sargent Merger Warrant and the Junior Subordinated Notes Warrant as described in paragraph (i) above, the shares of Common Stock held directly by Partners III as described in paragraph (ii) above, the shares of Common Stock held by Co-Investors III as described in paragraph (iii) above, the shares of Common Stock held directly by and issuable to TC Sargent pursuant to the Sargent Merger Warrant as described in paragraph (iv) above, and the shares of Common Stock held directly by TC Roadrunner as described in paragraph (v) above.  As the managing member of HC Equity and the general partner of HCI and HCI Management III, HCI Equity Partners exercises certain authority over the investment decision-making process of the other Reporting Persons through its board of directors, and, as a result, the directors may be deemed to have shared power to vote or direct the vote and shared power to dispose or direct the disposition of the foregoing shares of Common Stock.  The directors are Daniel M. Dickinson, Douglas P. McCormick and Scott D. Rued.  Board actions generally must be approved by two of the three directors.

The Reporting Persons expressly disclaim that they have agreed to act as a group other than as described herein.  The filing of this Schedule 13D by the Reporting Persons shall not be considered an admission that such Reporting Persons, for the purpose of Section 13(d) of the Exchange Act, are the beneficial owners of any of the shares of Common Stock.

(c)                                  On May 2, 2013, Thayer sold 816,487 shares of Common Stock, TC Roadrunner sold 1,711 shares of Common Stock, TC Sargent sold 1,717 shares of Common Stock, Partners III sold 177,512 shares of Common Stock and Co-Investors III sold 2,573 shares of Common Stock.  The shares were sold in an open-market transaction at a price per share of $22.46 to unaffiliated purchasers.

(d)                                 Except as stated within this Item 5, to the knowledge of the Reporting Persons, only the Reporting Persons have the right to receive or the power to direct the receipt of dividends from, or proceeds from the sale of, the shares of Common Stock of the Issuer reported by this statement.

(e)                                  Inapplicable.

15

Item 7.                                 Material to be filed as Exhibits.

*Previously filed as an Exhibit to Schedule 13D filed by the Reporting Persons on May 24, 2011.

16

SIGNATURES

After reasonable inquiry and to the best of each of the undersigned’s knowledge and belief, each of the undersigned certify that the information set forth in this statement is true, complete and correct.

17

18

19

SCHEDULE A

HCI Equity Partners, L.L.C.

HCI Equity Partners, L.L.C. is managed by a board of directors.  Set forth below is the name and business address of each director of HCI Equity Partners, L.L.C.

20

EXHIBIT A

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k) promulgated under the Securities Exchange Act of 1934, as amended, the undersigned, being duly authorized, hereby confirm the agreement by and among them to the joint filing on behalf of them of a Statement on Schedule 13D, and any and all amendments thereto, with respect to the above referenced securities and that this Agreement be included as an Exhibit to such filing.

Dated: May 13, 2013

21

22

23